14 May 2019

FWS Armory: Pressurized Environments Firearms by Yoel

Ever since humans left Africa, we began the process of exploring and colonizing this world.  We altered the environments that we encountered to suit the needs and requirements of our species and in some ways, the altered environment shaped us as well.  When high-altitude air travel become a reality, the developers of those planes bottled surface-like atmosphere to encompass the plane's crew and passengers. The same will be true with the deep spacecraft and space habitats of our future; they will also need a pressurized breathable air bubble in the deadly vast of nothingness.In such delicate environment it might be wise not to conduct any violent acts that might endanger the integrity of the bubble walls or taint the air with gunfire shootouts. But given that the dwellers of those bubbles are essentially the same apes who march out of Africa that ain't likely to happen. In this installment of the continuing Armory Series, we will be looking at Firearms and cartridges designed for such pressurized environments: the Pressurized Environments Firearms (PEF)                   

Due to the fragment and multidisciplinary nature of the topic, the making of this article become a joint multi-national project involved researching and questing numerous individuals worldwide. From retired Sky Marshals to James Bond experts, all were drafted for the cause. With much gratitude, these are the peoples who made this article possible:

  • Retried Sky marshals- Stephen Rustad & Mordechai Rachamim.
  • Cartridge manufacturers: Jim Maltenieks president of American Ballistics (ABS)
  • Peter Pi, CEO of CorBon, 
  •  Cameron Hopkins, CEO of Super Vel
  • Cartridge collectors- Pete deCoux & Mel Carpenter
  • Weapon experts- Hrachya Hayrapet & Maxim Popenker
  • Mel Zaid- founder and former CEO of Technik Inc.
  • David Louis Buehn, CEO of Rough & Ready Inc.
  • John Edward Shields kin.
  • Jeff Wybo of James Bond Canada.
  • Grant Hutchison of Oikofuge for his Coriolis Effect trajectories' diagrams.  

The Misconceptions of Firing inside a Pressurized Airliner or Spaceship
The common conception of pressurized vessel hull breaching has been polluted by Hollywood “science” for decades resulting in numerous misconceptions regarding the vulnerability of aircraft or spaceship to gunfire onboard along with over-dramatized the outcomes of such bullets' holes.   

The Integrity of the Hull Materials
First, it might be wise to remember that airliner or spaceship walls aren't much more than thin tinfoil. Terrifying as it maybe, all it takes is a few millimeters thick aluminum to be sufficient to hold sea level pressure gauge against outer-space hard vacuum or near vacuum of high altitude. But holding atmosphere in is only one of the properties aircraft or spaceship skins (or hulls) have. Both air or space vessels operate in an environment with extreme temperatures which need to be thermally isolated to maintain cozy room temperatures inside. Aircrafts hulls are also used to moderate the external noise while spaceships hulls have to shields the inhabitants against deadly radiation, both natural and from the ship nuclear engine (if exist).All of that means relatively thick external walls of our spaceship or space station.  The wall's lining are likely serve as energy absorber in case a bullet breach the inner wall, similar to a Kevlar-like armor material. Not only may such filling stop a bullet before it pierces the outer shell, if the bullet manages to drill its way all through the lining material, then the lining usually will compresses between the inner and outer walls, due to its tendency to expand and thus, sealing the hole quite effectively.           

The Minute long Hurricanes
One common trope of poplar media and Sci-Fi is that a breach in the hull will produce a mighty airflow that lifts people like tree leaves from whereabouts they were and throw them through the hole into the void. Such hurricane -like flow, as usually depicted, are long enough to have dramatic scenes where the protagonist/s have ample time to grab some static lifebuoy or each other and if the breach is an airlock door, enough time to climb against the air stream to push on the “close-the-airlock-now” button.
However, the reality is very different…sorry, Hollywood. Any hole in the hull big enough to create an initial flow with initial velocity similar to a hurricane ought to be major explosive decompression. Given this, the room where the breach accrues, the unlucky inhabitants will be killed from violent acceleration before been thrown to space. Any hole big enough to create such airflow will decompressed the airplane or spaceship very quickly, as the pressure drops so does the airflow so a minutes-long howling stream is partially impossible.     

Suction through a Bullet Hole
Inspired by Mr. Bond’s remark about being sucked into outer space by or thrown through a bullet hole, it been a common misconception that the pressure gauge between the pressurized cabin to the near vacuum outside has enough force to squeeze human body out of this small hole. That misconception is manifested in the visual media with the following generic steps: an individual (usually the antagonist) is picked by the none-realistic flow and throw against the wall, plugging the hole, after a short moment of silence the unfortunate victim start to compressed and vented out through the small hole like a human toothpaste tube until the whole body drained out and the outer shell of the victim is blown out too. That is complete rubbish. The maximum pressure difference between the cabin and outdoor is 1 Atmosphere (ATM) which equal to 1 Kg force to each 1 square centimeter of hole or 14.7 pound force to each 1 square Inch of hole. Such low force can't possibly break the human body into a paste; human skin is fairly durable and elastic. There were many examples both planned experiments and accidents where humans and animals were subjected to full or partial vacuum exposure and they confirm that the skin can stretch and hold body interior without bursting.
Several experiments done in the 1960's on dogs shown that even after the “guinea pigs” were subjected to rapid decompression to near vacuum conditions, those dogs die off quickly and their body were swell to approximately double their normal size without any damage to the skin. (Poor dogs!).  It is safe to say that any bullet holes won't be sufficient enough to force to tear down human skin if placed to seal the hole. Unlike the American tale about the little Dutch boy who save his hometown of Harlem by plugging a leaking dike with his little finger, in the case of leaking spaceship that boy could actually close the hole using his bare finger without any risk to the boy or the finger! Such finger partially exposed the 3 Kelvin coldness of space will be rapid cooled down by thermal radiation. My back-of-the-envelop calculations show that the heat loss via radiation to the 3K of space is equal to -60°c / -76°f heat loss in still air so frostbites are due, hence - more serious measures are needed to fix the leak after the initial plugging.     

Unrealistic Short time to Full Decompression
As with the hurricane force flows and the bone crashing suction, the time left to the inhabitants of a leaked craft is overly underestimate by popular media. Generally, symptoms of hypoxia will appear when the cabin pressure dropped to quarter of atmosphere.  So, conservative calculations will mark that threshold as the minimum pressure allowed for estimating the time left for crew and passengers to take action to save their lives. It also important to understand that such time calculations are totally irrelevant to an airplane, only for a spaceship. Airplane isn't operate in a total vacuum and its life support system isn't close system. Airplanes are venting out air regularly through many small holes and cracks in the fuselage and the indoor pressure is controlled by outflow pressure valves. Fresh outside air is routinely compressed, cooled and filtered and introduce to the pressurized cabin onboard an aircraft. If a bullet hole or other holes punctures the hull, the plane's pressure control system simply closes one or more of the outflow pressure valves to compensate the added leak source to the already leaking cabin. Unless some major hole was formed, regular pressure control system can handle pretty much any gun spree aftermath.
Same isn’t true for spaceships; due to spacecraft carry their own air onboard in a form of either liquefied or high-pressure gas tanks (usually oxygen and nitrogen). As the case with airplanes, spaceship can't be totally 100% leak-proof. Some very slow leakage will be always presence and it the duty of the life support system to monitor and supplement those losses from those stored tanks. Now you might ask yourself what if the rate of those life support systems fill up the loses be enough to counter the air leakage cause due the some bullet hole, does the crew or passengers have ample time to patch the hole before run out of air?
Well, consider the worst case scenario that the life support system been damaged in the cross fire or deliberately, the time to fix the leakage is confined to the air reservoir in the cabin. A very simply equation of cabin decompressing assume a sonic flow (Mach 1) at the hole opening and isotherm (constant air temperature) will results for room temperature 21% oxygen-79% nitrogen mix and factor of four in air pressure drop the following solution: t(sec)=2*V(m^3)/A(M^2)Where t is the time that will takes to air pressure to drop to a quarter of initial pressure, V(m^3) the cabin volume and A(m^2) hole or holes combine cross area.
Example:  the International Space Station (ISS) Pressurized volume is 931.5 m^3, if one of the Russian cosmonauts had been using their Makarov PM pistols that was carried up until 2008 in their Soyuz spacecraft to disable the life support system and then put a hole in the ISS wall, how much time the other crewmember have to plug the hole? A Makarov PM is chamber to 9x18mm Makarov round will leave 9mm circular hole of 0.000063585m^2. Craning the number in the equation to find it will take 29,299,363 seconds or 339 days. A far cry from an urgent problem as depicted in popular media.         

Why Catastrophic Result of Airliner Indoor Shootout isn't a Catastrophe
Above are listed several reasons why gunfire onboard airplane or a spaceship won't result in catastrophic loss of the ship & crew and any passengers. But what if such a loss in on of itself isn't the worst possible outcome?
In many of the cases of commercial airlines hijacking, the hijackers' goal was to divert the plane from its course towards a landing site sympathetic to their cause from where the hijackers could blackmail the government/s for the release and wellbeing of the passengers. A cold heart and cool headed decision could be made in advance by the government in charge for the safety of its people that a loss of an airplane along with its passengers is slightly better result of a hijacking attempt than a nation brought to its knees and comply with the hijackers' demands.
A nation allowed or mandate an armed security guard (like the US Federal Air Marshals) onboard airliners or spaceliners chose to take such risk with the hope that their decision will act as a deterrent to future attempts as the would be future hijackers factor in the fact that their hostages lives won't shields them.
The stakes were raised even higher after the September 11th attacks when it became obvious that religious zealot hijacker motive might be substantially different than just release of his comrades from Asian Dawn Movement, New Provo Front, or the Liberte de Quebec of out of prison, more like convert the plane into a gigantic Kamikaze aim at heavily populated buildings. In such scenarios, it isn't the lives of the passengers' weight against national security, it is the lives of both the passengers and thousands of civilians on the ground that at stakes if the hijack attempt won't stop ASAP. After the September 11th terrorist attacks the dilemmas of onboard armed personal have been almost disappeared as the cost of failure at stopping a hijack outweigh the sum lives of crew and passengers.
Challenges and Options designing Pressurized Environments Firearms

Not Shooting
It sounds odd to consider the option of not shooting as something weapon designers should factor in when sketching a new gun...but that isn't a wrong move at all. The purpose of a weapon, any weapon, isn't to kill per se but to impose the wielder will upon other. If that purpose was served without firing or even withdraw the gun from the holster then the gun severed its owner well. Thus, bestowing nearly all firearms the title of a “psychological weapon”. Douglas Adams, in his novel Restaurant at the End of the Universe, introduce such a gun, the "Kill-O-Zap" carried by Golgafrinchan ship's first officer. The features and appearance of the gun were explained: 'The designer was clearly not instructed to beat about the bush. “Make it evil,” they’ve been told. “Make it totally clear that this gun has a right end and a wrong end. Make it totally clear to anyone standing at the wrong end that things are going badly for them. If that means sticking all sorts of spikes and prongs and blackened bits all over it then so be it. This is not a gun for hanging over the fireplace or sticking in the umbrella stand, this is a gun for going out and making people miserable with.”'.When consider scenarios where armed agents of the state are facing unarmed civilians and those arms aren't meant to be concealed it pay off to have those guns of intimidating and menacing as possible.   

Not Missing the Target
Again, this is a no brainer. No one designs a gun to miss, but one should tune the design of the gun to be more suitable for fewer accurate shots rather than burst mode. In the densely packed spaces of airplane or spaceship, there is a heightened he danger of hitting bystanders. It is more desirable to have a gun with a small ammo capacity forcing the wielder to count any shot as it was the last. These questions were bedrock during the formation and training of the premier US Army Counter-terrorist unit, DELTA Force. One of the original operators, Eric L. Haney writes about the challenges of CT operations onboard aircraft in his excellent 2002 book Inside DELTA Force. He discussed that airplanes are “crammed with people” and even the founder of DELTA, Colonel Beckwith, said that terrorist-held airplane would be their toughest tactical environment.
The Unit would have to adapt (or train like you fight) to the special conditions of storming airliners packed with hostages and a few hijackers. The then handgun of DELTA back in the late 1970’s was an improved accuracy Colt M1911 .45 ACP and these original operators were trained to fire one round at a time during such engagements to maximize actually hitting the target not missing the target and creating a worst situation. Another option for today’s high-speed, high-tech door kickers is to mount fancy optics like red-dot and holo sights alike to increase hit probability of each shot.

Not Over-Penetrate the Target
Even after a precious shot hit the target, there is the danger of over-penetration.  In this scenario, the projectile could exit the other side of the tango and further travel, sometime in different direction, and endangering the bystanders and the vehicle itself. A common solution is to use ammunition that deform, tumble or break inside of the target body and dissipate its kinetic energy completely without emerging out. Ammunition types such as hollow point, soft-nose, fragment etc. exist and use or used by various air and sky marshal programs and armed pilots worldwide. Citing again Eric L. Haney’s Inside DELTA Force book and Colonel Beckwith's own book on the CT unit he founded, the original operators of DELTA selected use of the .45 ACP round over 9mm due to lower velocity and less risk over-penetration back during the late 1970’s spin-up of the Unit. 
However, very shortly, DELTA would adapt the 9x19mm H&K MP5 SMG for general CQC environments (which included airplanes) very much like the vast majority of Special Operations CT units at the time. While online firearm forums and videos are filled with people discussing the use of certain calibers for airplane engages, 9mm vs. .45 vs. 5.7mm vs. .357 SIG, we have to remember that the US Federal Air Marshals use SIG Sauer P229 in .357 SIG (the first gun I ever bought! -William) and that most Counter-Terrorism units back in the day of the apex of airliner hijackings used the rock-solid MP5 SMG platform for storming planes. Take that for what you will.     

No Penetration of the Hull
In case the shooter missed the target, it is important that the bullet will not penetrate the airplane or spaceship inner and outer walls. This will require calibrating of the ammunition's penetration performances to be lesser than normal ammunition loads, so that the walls resistance capability will ensure that any stray shots won't go through and through. As stated above, this deteriorates rapidly into a caliber debate online, but in the realm sci-fi there is often customized designed weaponry or settings for VBSS style boarding operations.   

No Ricochet
Once a bullet leaves the gun, you cannot take it back and this regret could be made the worst that could be managed by yet another desirable feature needed in PEF ammunition: that the bullet won't ricochet after hitting the wall and bounce back to endangering any innocent bystanders or the endanger the structure of the artificial environment. Many of the bullets developed with low over-penetrate in mind will likely be engineered to break inside the target are also likely to break when hit the hard surface of the wall and not ricochet.   

Bullet Disintegration and Shattering
In any future scenarios of shootouts in various freefall environments such as the familiar spaceship or even your local space station, it would be very preferable that the bullets won't break or shatter into free-floating tiny fragments that might be inhaled by the crew or clogged inside some vital piece of futuristic machinery like life support or the warp core.  After battle cleanup procedures in these types of environments could be a real pain in rear if any missed gun resulted in hail of debris. 

Not to be Misused
In many of the plausible scenarios where Pressurized Environments Firearms (PEF) are or will be present and used, the PEF will be the only gun on the scene.  In addition, the PEF's wielder, likely a member of the “authorities”, will face an unarmored opponent with inferior weapon among scores of non-involves. As such, various methods of preventing the PEF misuse by the opponent or bystanders might apply to the weapon system. The easiest will be mechanically constrained the gun to the user, tether it to the user belt or issue holsters design to prevent the gun to be surprisingly drawn by other than its user (like a current pistol lanyard). Other options include personalized guns via technology, AKA: Smart Guns, which enable the use of anyone but the gun authorized user/s.
This technology has been seen in Star Trek and in the Bond universe with the Walter PPK from Skyfall. Another thing to consideration, when the PEF is concealed and the user travel in plain-clothes, as is the case with air/sky marshals. The passengers and crew will automatically assume and identify the current wielder of the gun as the marshal and any other individual on board that try to wrestle and fight the wielder as the bad guy. The last thing a marshal needs while fight one terrorist is to repel several John Wayne wannabies. If the gun is tethered to the marshal or the smart gun alarm screams "unauthorized user" the passengers will be less incline to regards the man with the gun as the de-facto marshal.

Hearing Protection
Firing inside the cumbersome corridors and bunkheads of spaceship, the gunshot blasts will echo back from the metal walls around you. Without ear protection, the PEF user and any non-involves could suffer permanent/temporary hearing loss. Even a temporarily hear loss in a tactical situation might be fatal in the middle of combat as it could reduce the user situational awareness. Wearing ear protection is optional, but it too might reduce the user's situation awareness and not a real option if the plain-clothes user carries the PEF as concealed gun. To reduce the gun blast decibel level, all the technologies currently used here on Earth could be used such as silencers, which are a good option as well as more exotic such as totally enclose piston cartridges and captive bolt guns. For more in-depth analysis on the topic of silence firearms check my past FWS Armory article.

Free-fall and Low-Gravity Scenarios
The lack of gravity or even a low-gravity environment would influence many aspects of gunfights inside the pressurized cabins. It is gravity that mount foots to the floor, braced against the gun's recoil and its gravity that grab and pull the hot spent brass down.

Recoil Management
Recoil is the most over-appreciated problem people might associate with firing a gun in freefall. The truth is that gun recoil, in terms of momentum, is pretty minuscule compare the combine mass of shooter and the gun. It is easy to calculate the backward velocity the shooter acquire by multiplying the bullet mass with its muzzle velocity dividing by the sum mass of the shooter, gun and yet unused ammo. For example: a 38 Special has a mass of 9.5gr and muzzle velocity of 900m/s, divide the multiply by 80Kg of fully armed security guard will results in one guard slowly drifting 0.1m/s backward when fired.
All of this, of course, is purely theoretical scenario where someone in zero G caught in midair when bullets are flying and tries to return fire. There is no tactical advantage for such indoor space fighting leap of faith maneuver, giving the confine space those spaceships and station are likely to have the smart move is try to take cover by held one of the many handles the walls are covered with one hand and brace yourself to the wall similar to a military prone position while using the other hand to shot at your enemy. Such position the shooter present a much smaller target to hit while the anchoring keep him in place and not drifting away from the recoil. In such scenarios, a handgun will preferable compare to long gun as it could be used one handed. An revolver is better than a traditional autoloader handgun since it could be easily used by either hand without spent cases ejected in the shooter face and with the ability to clear dud round by pulling the trigger again while autoloader will required both hands.

Spent Casings
The problem of hot brass spewed at one own face or your comrade face isn't anew, it is one of many factors tested in any new gun trials especially back in the days of packed soldiers line and volley fire. One consideration the developers and users of territorial gun never had to trouble about is their spent cases floating all over the place! Such luxury isn't the case with hot brass in weightlessness, a case will be ejected from the ejection port and keep on going till it hit something or someone where it bounce and continue floating randomly across the room as Newton said when he laid down the law.  Such cases are more than just a nuisance to be cleaned up after the gunfight, the metallic cases could be wandering and be caught into and inside some important machinery or short circuit some electronic.
Depending on how hardened the space habitat support technology it might be wise to contains the cases from leaving the gun. Brass catcher came to mind as an ad hoc solution till you realize that the catcher relied on Earth gravity to settle the cases in the catcher bag, I leave it to the reader ingenuity to think of some one direction value that allows the cases to be ejected to the bag but prevent the floating cases to return back toward the ejection port. Caseless ammo could pull the trick if such technology could ever be reliably and cheap back on Earth which at the moment doesn't seem to be the case (pun intended of course).
The answer may lie in rather ancient tech – the wheel gun. Empty cases and dud rounds aren't ejected after each shot but discharged at reload and it possible to configure revolvers to have quick removable and replaceable cylinder that could be swapped the empty with fresh one. The cylinder could be reusable with chambers for regular cartridges or disposable cylinder with factory preloaded bullets, charges and primers. Either way an empty cylinder is easy to grab and return to the vest pouch or find during the aftermath clean-up when six or more empty cases aren't.   

Bullets' Fragments 
As stated in the “Not to Disintegrate” segment above, it be wise NOT to use any ammunition that tends to break and shatter into fragments if the round misses its intended target. When consider both the requirement of not over-penetrating and the need for the projectile not to fragment into pieces most of the frangible ammo is off the table with the exception of bean bags rounds that in essence a small load of buckshot enclosed in a small flexible material.

Thermal Convection
One of main mechanism of heat removal and cooling is the natural convection. A warm body in a cooler surrounding fluid will warm the closer layer of the fluid via thermal conduction.  The slightly warmer layer will be less dense than the rest of the ambient fluid and thus lighter and by bouncy will rise upward taking with it the body energy and exposing the body to new cooled fluid to continue the process once more.
Such phenomena is greatly depended upon gravity, the weaker the gravity the less heat is removed by convection and at freefall heat can removed from object only by slow conduction and thermal radiation. The absence of gravity is a factor in everyday life aboard the ISS, from compatible ambient temperature for the inhabitants to force convection fans for electronic racks. It will also be a consideration when choosing what guns to use in such environments. Whenever gun is fired it will heat very fast and very hot and it will takes a considerable longer to cool down.
Naturally Null-G gun users will gravitate toward low rate of fire and small ammo capacity guns as any repeatable fire will dangerously heat up the gun. Any expose metal parts will be covered with heat shielding and barrel shroud. This means that your portable mini-gun or reaper gun is ruled out. The danger of cartridge cook-off in the firing chamber will be worry at any case of close bolt firearm. This could eliminate the use of caseless weaponry due the much higher danger off thermal cook-off as H&K found during the development of the G11. The natural candidate again for such constrains is, once again, the revolver. The cartridges are kept in the cylinder and not waiting in some firing chamber to cook, it has low ammo capacity and low ROF, but likely more than enough to end the fight before the gun's parts start melting and it much more resilient to high temperatures and rapid heating than its autoloaders counterparts.
Coriolis Effect
Currently there are only two methods of generating artificial gravity.  The first one is to constantly accelerate your spaceship toward your destination about half of the way, then flip turn the ship 180 degrees and constantly decelerate the craft to a halt at the destination. Whatever acceleration the ship performs is the amount of artificial gravity the inhabitants will experience onboard. Such vessels are call Torchships and their drive is calls Torch drive. Sadly, while the technologies that allows a ship drive to produce constant acceleration close to Terran 1g level are within known science they are still appear to be off the table for a long way to come. Of course, it couldn't applied to space stations or terrestrial colonies on the surface of low gravity bodies, like an asteroid mining facility.
A simpler approach is to spin a segment or all of the spaceship or space station around an axis at a constant spinning rate to make, via centrifugal force, an artificial gravity on the inner walls of the rotating canister where the “up” direction is toward the axis and the “down” is away from. The magnitude of the gravity is determined by two factors: the spin rate, which is uniform everywhere in the spinning segment of the ship or station and the distance one is from the axis. Therefor to produce uniform value of gravity that is identical to the inhabitants and perpendicular to the floor, a spin gravity dictate the habitat to shape along circular geometry: ring, cylinder and torus. 
Mostly, the spin gravity is identical to the real one. Sure, you have variation in the gravity if change your distance from the axis when you climb a ladder and such but since the living space is arranged circularly that usually unnoticed. Another thing that difference from real gravity is the influence of the Coriolis Effect. Whenever a body moves in the rotating set of reference perpendicular to the spinning axis it will experience strange drift aside perpendicular to its velocity. The magnitude of the force for a given spin rate will be determined only by the body velocity in the rotation plane which mean that a stationary body won't feel it.
The direction of the force will always be perpendicular to velocity and pointing to the opposite side of the rotation direction. In plain terms, any object traveling in the rotation plane: up(toward the axis), down(from the axis), Westward(spinward) or Eastward (counterspinward) will seem to be caught in unfelt tornado winds, one that its axis parallel to the ship or station rotation axis but reversed in direction. For upward movement the body will drift spinward, for downward movement a drift counterspinward, for spinward it be downward and for counterspinward it be upward.
Moving objects parallel to the spin axis will drift too, the motion parallel on be effect but the object still fall down to the floor cause by the artificial gravity and will drift counterspinward like an object dropped down. Normally here on Earth we neglect Earth rotation and the influence of Coriolis Effect when it comes to firearms' ballistics since Earth complete a revolution every 23 hours, 56 minutes & 4 seconds. When launching projectiles inside a rotating can which revolve several time a minute such force couldn't be written off. The key factor determine the bullet curved trajectory is the ratio between its velocity relative to the surrounding (muzzle velocity initially) to the shooter velocity relative to observer outside of the spinning set of reference. Since the shooter is traveling with the rest of spinning ship or station his speed is the rim velocity. If the shooter is facing toward the spin direction, spinward, the bullet will suffer greater bullet drop than the felt gravity should inflict. When the shooter turn back and fire counterspinward the bullet will gain a 'lift' thank to Coriolis, for a velocity ratio of 1 the bullet will fly in a close circle around the rotation axis with constant distance from the floor till eventually air drag will rob the bullet's energy and it slowly decent to the floor. Shooting upward toward that ladder climber the shooter ought to aim slightly counterspinward or keep missing as the bullets drift spinward. In contrast, the climber need to aim spinward to hit the shooter at the bottom of the ladder. Such drift could create some bizarre circumstances:
If the ladder is inside narrow tube as one inside the station's spokes the drift will drive the two shooters' bullets hitting the tube walls instead each other.
If the station designers bless it with circular corridors and you have a tango up spin barricade you could shot counterspinward and your bullets will complete a full round and bite the enemy in the rear! If an enemy is placed on a platform directly overhead a shooter at ground level can aim spinward to land bullets on his head, the enemy can also hit you by fire spinward too. Such opportunistically trajectories greatly depends upon that velocity ratio and clear field of view and firing that doesn't really exist in small space stations and always never in spaceships. For the rim velocity to be in the magnitude if typical gun bullets, which are in the hundreds of meters per second the space station should be in the range of couple hundreds meter in radius, for a O'Neill Cylinder 8km in diameter rotating once every two minutes the rim velocity is 200 m/c, comparable to slow sub sonic-pistol ammo, if the bullet is very aerodynamic and fired counter spinward it will cruse a significant path above the ground before falling. Every shot against a tram running parallel and close to the axis or shot down one slowly falling Captain John Sheridan will have to account this drift too. 
Pure Oxygen Atmosphere
Here on good ole Terra, we breathe an atmosphere compose of 78% Nitrogen, 21% Oxygen and less than 1% of additional gasses in one atmosphere pressure or 1 Atm. Such a breathing mix might be apply to future space station, planetary basses and spaceships as it currently used in the ISS previously used onboard the American Space Shuttles and all of the Soviet/ Russian spacecrafts and space stations. But, other atmospheric mixes had been used by NASA: all of the spacecrats prior to the Space Shuttle were pressurized with 0.2Atm pure Oxygen and the Skylab station used 0.3Atm with 25% Nitrogen and 75% Oxygen.
An Oxygen-rich low pressure reduce the mass of the air carried to orbit and the reduce pressure allows reducing the craft structural integrity, further lowering its mass.
A lower pressure also minimize the pressure leakage and reduce the mass losses overtime.
The use of pure oxygen atmosphere have additional advantages, using one component atmosphere eliminate the need to carry and store two separate gas tanks on-board and eliminate the need of complex gas mix regulator and sensor constantly measuring the atmospheric make-up.
Since current soft spacesuits use pure oxygen, any EVA will require the astronaut leaving a Nitrogen-Oxygen breathe mix to preform long pre-breathing to purge the Nitrogen from his/her blood or risk suffering the decompressing sickness (also known as diver sickness or the 'bends'). Astronauts aboard ISS or the Shuttle need more than an hour of pre-breathing. When using pure Oxygen inside the habitat that all pesky pre-breathing is unnecessary.
Another advantage, Nitrogen is very rare outside of planet Earth, only Saturn's moon of Titan is known to have large quantities of it. Oxygen, on the other hand, is abundant everywhere, Lunar regolith is half by mass Oxygen and easy to extract by baking the regolith to high temperatures. Shipments of Oxygen from Lunar surface or asteroids to replenish ships' and stations' accumulated slow air losses or provide ever-grow space civilization is much easier than pull Nitrogen from Earth gravity well or hauling it from distant Titan. With those great advantages come serious disadvantages, first among them is the flammability issues of even barely flammable material socket inside such a pure Oxygen bath.
The fanatic over exaggerate fear of pure Oxygen atmosphere is rooted in the horrible 1968 Apollo 1 accident where while ground testing a fire broke in the pure Oxygen environment of the capsule burning the three astronauts alive. It is a common misconception that NASA switch to Nitrogen-Oxygen mix as a result of the accident, in fact the Apollo Program continued to use pure Oxygen air till the last mission, Apollo 17 and use mix on the ground, switching to pure oxygen on the rocket ascend to orbit.
Another misconception is that the Apollo 1 inferno is solely the fault of the pure oxygen atmosphere, the reason the fire break out and burned the astronauts alive is caused by the ground testing conditions. The lunar command module was over-pressurized to 1.2Atm in order to check the module tolerance to 0.2Atm pressure gauge it will endure in space. The combination of 1.2Atm of pure oxygen and the full gravity of Earth that induce convection currents feed the flames with oxygen and remove the carbon dioxide created the perfect storm that consume the module and the astronauts. A low pressure pure Oxygen is still dangerously flammable though, the air contains as much Oxygen molecules as Earth atmosphere but without the damping effect of the inert Nitrogen any flame ignited have the potential to evolve to major fire. A future spacefaring civilization might chose to switch back to pure Oxygen environment cause of all those listed advantages and bite the bullet of greater flammability. Speaking of bullets; the nature of the atmosphere will shape the requirements and specification the firearms will design to operate in such conditions.
In such an atmosphere, the danger of muzzle flash, the unburned gunpowder residues, will force the installation of silencer mount to any gun. Hot brass pose anther ignition source and brass catcher have to be attach to any autoloader or use of revolvers instead. The lower air pressure will reduce the natural convection heat transfer, the guns will heat up very fast and will takes longer time to cool down. Any expose metal part should be cover in the equivalent of full body barrel shroud that prevents any contact between the hot metal to any flammable material if the gun dropped or fall down. Two unexpected perks of the lower pressure; firstly sound transfer reduced by the lower air density and with combine with the obligatory silencers eliminate the need of hearing protection. Second; the lower air density, a fifth of Earth sea level, meant that the air drag is also approximately fifth of what the bullet face in normal Earth air. Most if not all of the special purpose cartridges designed for reduced hull penetration and reduce over-penetration have terrible aerodynamic properties. A lower pressure cabin will allows such types of ammo lower velocity drop and larger ranges beyond their Earth bound specification.
Gunpowder contamination of human and life support
The living in closed life support environment mean that the inhale one takes was previously been someone else exhale (better brush those teeth! In such circumstances, polluting the air with gunpowder burning byproducts or unburned gunpowder residue could endanger the habitat's dwellers or the air recycling systems. The most dangerous of gunfire products is carbon monoxide (CO), a small amount of the gas is enough to poisoning human by bounding with blood hemoglobin. Several incidents of carbon monoxide poisoning in closed indoor firing ranges have reported and at least one report of battle field carbon monoxide poisoning is known during the Korean War when the accumulate CO produced by American bomb shells on North Korean bunker results in death from CO poisoning.
There is little to no available information about CO effect on the common air replenish systems used for space applications. It is likely that expendable chemical carbon scrubbers could scrub carbon monoxide as effective as they remove carbon dioxide. More advance systems like Sabatier reactor might be sensitive to CO and other gunfire products and may require to flash out the air to space after the gun firing was over as standard protocol onboard modern spacecrafts and stations when dealing with fire scene clean up. Minimize the air contamination will be prime necessity when designing the firearms, the best solution will be the totally enclose piston cartridges as any gunpowder product will be bottled inside of the spent case. Those spent cases will be later remove from the scene for safe disposal. In other cases, a suppressed revolver with special silencer shape filter mount on the muzzle will filter out the dangerous components from the muzzle flash while allows the bullet to exit at the other end. Those filters, like the spent totally enclose cartridges, will be disposed of after the battle.
The Colt Shields Revolver
From 1968 to 1972, there were no less than 130 American airliners were hijacked and routed to foreign airfield by individuals armed with hidden knives or guns with often fully loaded passenger planes. This time period was called the "Golden Age of Hijacking".The reasons various for the hijacking varied from political stance to ransom money. Cuba was the destination of choice for most of them as it was the nearest hostile to US landing site and it was pictured in the dazed minds of many of the hijackers as the “perfect social worker paradise”.
The airline company that toke the lion share of those hijacks was Miami-based company named Eastern Airlines. Eastern had no less than 45 of their aircraft hijacked, 27 in 1972 alone. The company launched expensive and extensive security program and the manager of operational security, a man name John Edward Shields, was instated to provide full corporation with the FAA and their newly Sky Marshal program. Mr. Shields wasn't supportive to say at least, he believed that the best place to stop a evil-doers was on the ground with security screening stops rather than a high altitude shootouts. Shields was also vocal regarding the quality of the men drafted to the Sky Marshal roles or more precisely their lack of quality… listed reports of Marshals dropping their revolver or even forget their service weapons in the plane or airport restrooms. Eventually, the FAA pressured Eastern Airlines, like other airliner companies, into cooperative understanding and Marshals boarded Eastern planes.
Mr. Shields, however had a plan B, he made while trying to hold the FAA Marshals out, if armed men are needed on the planes, they be Eastern finest: the aircraft's pilot and co-pilot, not the FAA Marshals. He turn to Colt firearms company in a request to develop a specialized handgun to arm the two crew members with specific requirements for the gun. Mr. Shield’s laid out that ammunition should not penetrate the plane fuselage, ricochet or over-penetrate the target(s).
To avoid any malice use on board, on the airport grounds,or at pilots’ houses, the gun and ammo would be separated; one pilot carry the revolver without the cylinder and the other the “revovlerless” cylinder. The gun would have been assembled at the cockpit when the two crew members were together and then locked in a onboard safe to be used when if ever needed. The revolver couldn't be loaded with a regular cylinder from a similar firearm and vice versa - the cylinder is useless without its revolver, das if any of them is stolen or taken from either of the pilots they can't be used.
Colt directed the interesting requests to one of their subsidy companies: Colt Technik of Jericho, New York. Colt Technik converted small number of Colt revolvers to test prototypes mules.
 While firm numbers are unknown, at least three prototypes are known. Trooper MK III and Lawman MK V were modified to accommodate a black six shot cylinder made out of plastic called Zytel. In each cylinder were six stainless steel inserts, each one of those inserts contain primer, gunpowder, sabot and a brittle projectile made of a kind of gypsum called Plaster of Paris (PoP). The projectile is too brittle to engage the barrel rifling so it rest on plastic sabot which latch to the rifling instead. The inserts are firmly placed in the cylinder and can't be replace individually, loading and reloading the gun was done by replacing the all used cylinder with fresh one. Among the changes made the most notable is the absence of the ejection rod, as no spent cartridges are needed to be ejected the rod was trimmed completely. That trimming is even more distinguish in the case of the Lawman MK V conversion as it had a nice under barrel rod cavity left empty. The guns were tested and indeed, the brittle PoP projectiles found to be suited to the task, they could easily penetrate into human body and fragment without over penetration and stray shots shuttered when hit aircraft aluminum walls. Technik submitted their designs, manufacturing drawing and test results to Colt. However, Colt never delivered any of those guns to the airline. The Eastern Airlines board of directive, after convinced to allowed sky marshals to board Eastern airplanes, found no point in arming and training their pilots to prevent hijacking when the airline company already paid the marshal salary while losing the price ticket of the chair he sit in.
Colt latter tried to sell the concept of designated swappable cylinders as a less-lethal weapon for Law Enforcement and civilians, with the PoP bullets were replaced by rubber “riXng” bullets. Colt’s attempt, however, never bear fruit and the all idea of swappable cylinders revolver was scrapped. Number of converted revolver and cylinders were later sold to private gun owners and retailers. One interesting plot twist is that whenever one of those guns surface for sell it is labeled as “Sky Marshal” or “Air Marshal Revolver”. To the best of my research efforts, I doubt if Colt ever proposed the gun to any air/sky marshal program domestic or foreigner.
It is likely that the name was part of creative gun retailer marketing strategy to associate the strange gun with the well-known Air Marshals.
John Edward Shields pass away a few years ago and it is almost certainly that he was aware of the name attached to “his” gun. It is likely that John wasn't pleased with the idea that the gun that he set the develop and deploy to keep the Sky Marshals out of Eastern Airlines planes had been rebranded as “sky marshal” or “air marshal” revolvers. According to Technik founder and CEO, Mel Zaid, the gun or project never had a proper name, only number designations. There is also no clear reason to believe Colt ever gave it a name after their client turn their back on further funding. I propose a proper name to this interesting Colt revolver and I hope it will somehow stick. I'm suggesting that the name “Colt Shields” be the honoree name to these revolver, since I think Mr. Shields, a decorated USMC aviator, who serve in both WW2 and Korea, and his initiative are deserve to be heard and remembered.
Pressurized Environments Cartridges
Under that loose term of “Pressurized Environments cartridges” every cartridge that either issued to or developed for armed individual to be used inside a plane, either air/sky marshal or armed airliner crew member, in order to deter or stop mid-flight violent behavior be listed below.

The first US Air Marshals, or Sky Marshal as they called back then, were drawn from the ranks of the Treasury Department and U.S. Customs and Border Protection with the guns and ammo of those newly minted Marshals would carry the same guns: the then new snub nose .38 Smith & Wesson Model 60. The cartridges that were loaded into the S&W Model 60 was also new stuff, the .38 Super-Vel. The Super-Vel was the invention of one man, Lee Jurras, who combined the finest gunpowder available with light weight hollow point aluminum bullet. The result was the handgun projectile with a muzzle velocity of 1200 fps, slightly above the speed of sound, and with conjunction of the expandable nose tip provided great stopping power with minimal risk of over-penetrating of the target. The stray bullet, however, had no difficulty to cut a hole thru the plane skin or interior partitions. So much so, that the co-pilots, according to Stephen Rustad, jokingly suggest that if the need arise to shot toward the cockpit direction to keep missing to left side of the cockpit where the pilot set.
The Air Marshals nicknamed the Super-Vel cartridges as” Jets” but not just because they boarded and defended jet planes. During the lone and extensive training in that the range, the Marshals noted the distinctive sound of the new cartridge. As if the supersonic crack the potent .38 Super-Vel made sound like a jet engine make when an airplane lifts off.

Glaser Safety Slug
The Glaser safety slug is a frangible bullet. The bullets hollow head contains small birdshots plugged by polymer ball at the bullet tip. Several calibers available and the two possible sizes of the birdshots are indicated by the color of the bullet's tip: blue or silver.
The frangible structure of the bullet is deigned the break and fractured inside the target body deliver its full kinetic energy without over penetration.
In case of miss, the Glaser Safety Slug is less likely to ricocheting when the round hits a hard surface.For such reasons, the Glaser is ideal for operation in tight and crowded spaces and conditions as the danger to bystanders is minimal. Although not developed in mind for air marshal usage, the US Federal Air Marshall adapted and carries those rounds during the 70's & 80's. The preferred caliber was .38 special as back then the Marshals still carry those compact revolvers.
The cartridge was replaced sometime in the late 1980's with some unknown conventional hollow point round as those were much cheaper than the Glaser.

Speer Gold Dot .357
On the morning of September 11th, 2001, the US FAM program ranks were dwindle down after decades of stillness to as low as 33 Air Marshals. Their guns and ammo were basically unchanged since day one of service, a snub nose revolver in the .38 Special. And then came the events of September 11th, came and change everything. The FAM was pumped with more expansive budget, manpower, and new management. The FAMs were issue a new gun, the compact Sig Sauer P229 that was paired with the SIG developed and unusable .357 SIG caliber. This may seem like an odd choice that is made clear if you examine who was task with this rapid built-up of the now-vital Federal Air Marshal program: Thomas Dewey Quinn…a former Secret Service agent. Quinn was assigned the job of FAM director and the influence of his the years under Secret Service are fully on display with, among other things, in the weapon selection: the P229 was the standard handgun of the Secret Service. The cartridge used by the Marshals in their P229s is Speer Inc. Gold Dot .357 SIG 125 grain bullet.

The Bingham Ltd; Devastator 22LR
The Devastator was a cartridge produce by a small cottage manufacturer named Bingham Ltd from Norcross, Georgia. The mostly forgotten company specialized in drilling bullets heads and filling them with miniature canisters of explosive lead Azide making them to explosive bullets. The Devastator was the name of their explosive tip 22LR. The round was intended for vermin control and small game, the tiny explosive purpose was to fragment and mushroom the bullet upon entry into the target inflicting damage similar to larger calibers, or so Bingham Ltd ammo was advertised. The company and the round were almost totally forgotten if not one incident. On March 30, 1981, John W, Hinckley Jr attempt to assassin President Ronald Reagan using a Röhm RG-14 .22LR loaded with six Devastator rounds. Hinckley fired all the six rounds at President Reagan, but he was hit by a ricochet bullet that didn't explode.
Only one of the rounds explode, the one that hit White House Press Secretary James Brady, who survived a head shot from that so called Devastator round (albeit Brady remained permanently disabled from the shot). When interviewed days later, Sandy L. Brygider, head of Bingham Ltd, he claim among other things that the Devastator was designed for “Sky Marshals”. There is no evidence supporting Brygider claim and it appear that it was more of Brygider's attempt to whitewash the fact that Bingham Ltd products were just used in attempt to take down a president. Brygider claim, however, did forge the myth that FAMs were issued Devastator rounds.

The MBA; Short-Stop
 MBAssociates is best known and remembered for their Gyrojet weapon system, a revolutionary small size rocket ammo. Less known are their less-lethal family of products. One member of this family is the Short-stop, a miniaturized beanbag compressed and loaded into .38 Special cartridge. When fired, the bag is engaged with the barrel's rifling that spins it up, when leaving the muzzle, the centrifugal forces unfold the bag and increase its diameter and the air drag, the increased air drag slows the bag very rapidly. As result the Short-stop bullet have effective lethal range of 15 meter ( 50 feet) with further sharp decline in velocity and energy and the bag extended size and plasticity prevent it from penetrating wall or ricochet, the bag also wasn't intended to penetrate the target rather than deliver its kinetic energy as a deadly punch.
Although the Short-stop weren't developed with the Air Marshal market in mind, it become its only buyer. MBAssociates combine with Speer Inc. participant in U.S. Air Force trails in early 70's against Super-Vel (and maybe American Ballistics XAL?).
The Air Force specifically tested the cartridges penetration abilities against various airliner materials to evaluate the safety of using them in airliners. The Short-stop picked as the winner of the trial surpassing Super-Vel in accuracy and safety and chosen by the USAF to be issued its Mobility Airlift Command (MAC) aircrew members.
It isn't known what type of revolver the MAC aircrews were using.
When MBA decide to terminate their line of less-lethal armament in 1976, the Short-stop production was ended as well. There is no available information what cartridge the MAC was replaced the Short-stop with. It is also unknown if the current Air Mobility Command (AMC), which inherent MAC roles, aircrews are armed too and if they are, with what.         
American Ballistics; XAL
In the Early 1980's, American Ballistics, an American ammunition manufacture, produces and delivered an experimental hollow point cartridge for testing and evaluation trial for the US Air Force. The name of this cartage was XAL, an acronym for eXpanding Aluminum, reveals the material from which the bullet was made. Like the Super-Vels used by the Federal Air Marshals, the XAL were also a .38 Special caliber round and like the Super-Vels they relayed upon their low mass projectile to achieve supersonic muzzle velocity. Combined with the bullet large front cavity, the bullet would deform and flatten inside the body target and deliver all of its kinetic energy without the risk of over-penetration. About 1000 round batch delivered Eglin Air Force Base for testing. The relations with the former cartridge of the list, the MBA Short-stop, as well of the time table is a bit iffy. Both cartridges were .38 Special and the MAC was under the authority of the Air Force. Did the Air Force initiate a separate program parallel and separate to arm the pilots of other commands of the USAF? Did the XAL tested as a replacement to the Short-Stop? There were no clear answers to those questions. Whatever USAF intend was, the XAL was never adapted by anyone.     

Extreme Shock; Air Freedom (AFR)
Shortly after the September 11th Attacks, some companies rushed to capitalize the tragedy as with the given example of Air Freedom (AFR) cartridges, manufactured by the company called Extreme Shock. The AFR line of cartridges was based entirely on the idea of providing ammo that could take hijacker down without endangering the plane hull. All AFR bullets were hollow point filled with powdered Nytrillium and plugged with plastic cup. The powdered filling branded by Extreme Shock as Nytrillium was claimed to be sintered tungsten. The bullet is appeared to be frangible bullet similar the Glaser with different filling. The company went out of business in 2011, not before deployment of various calibers including some, like the 5.56x45mm NATO, that are most unlikely to be ever used onboard any airplane.         

The SP-8
The SP-8 (СП-8) was the only known cartridge specially designed for commercial airliners.
The cartridge was developed by КСПЗ, a Russian cartridges manufacture, by the order of the KGB in the early 80's. Back then at the long-range flights the pilots of Aeroflot, USSR national airliner, carried a Makarov PM locked in a safe in the cockpit, and onboard some international flights an armed plainclothes KGB agent was added. The cartridge is mostly hollow bullet variant of the standard 9×18mm Makarov PM cartridge. The projectile low mass and tendency the fragment upon impact was to insure no over penetration of airplane walls. Not much else is known of the cartridge, as far as my research went. Oddly, the current Russian government, like the previous one, still does not possess a dedicated Air Marshal program like the US and the question of whether or not the pilots of civilian Russians airlines are still armed is unknown as well. This is very odd considering the threat of terrorist aimed at Russian commercial airliners.

The Case for Space Boarding and Armed Boarding Parties
It is a common trope in many space Sci-Fi for an armed boarding party to breaking into an enemy spaceship or space station from the airlock or by cutting thru the hull. These space boarders are carried to battle by specialized small vessels called “boarding shuttles” or “breaching pods”. Common as the trope is, it is very difficult to justify it when consider the realities of space travel and space combat. Space is big…really-really big, and any fire exchange between spaceships will be conducted at a mind blowing distances. In such distances, even light may take seconds to minutes to cross the gap, making positioning the other ship uncertain. Any weapon used, be it missiles, railgun slugs or DE beams, ought to be fast to hit the target without been dogged by target ship’s evasive maneuvering or intercepted by point defense system. In this scenario, boarding parties that lack teleporter technology, are expected to cross the gap between the two battling warship rapidly and safely traverse the gap while carry the human payload back AND expected to slowly decelerate to halt when nearing the enemy ship, who shooting and maneuvering the entire time. Open season much? On top of that, if the target spaceship propulsion drive is nuclear, the ship’s own reactor is a deadly point defense system. Approaching that ship from anywhere other the nose direction will dose the boarding team with danger amount of radiation.
There are three possible scenarios of spaceborne boarding: brazen, stealth & or-else. The first is the most common in Sci-Fi, the brazen boarding is the space equivalent of brazen robbery, in mid-combat, when missiles flying around the daring ship ram its opponent, breaching the way for space marines to step and board the enemy ship (as seen in Arcadia of My Youth) . Sometime the ramming is done by the ship dispatching several small shuttles or pods each carry a small number of marines to achieve the same goal.
The second method is the stealth boarding tactic. The ship is quietly approaching the target without alerting anyone and latches on to the target vessel. The boarder will then start to cut into the ship skin to open their way inside. The problems with those two methods are clear; space is a sensor-friendly environment as well as weapon friendly. There are no obstacles like rain or horizon to block line of sight or line of fire. Making through the gap between the two warships without noticed is nigh impossible, so there is no change of stealthy docking. The brazing closing pods are also not good. Any ship in combat worth its salt, could track the incoming pods and either maneuver away from them or blowing them out of the water, or likely both. Bye-bye space Vikings.
Before unveil the third approach to boarding, it is important to examine the reasons one might need to board another spaceship. Destroying the enemy ship is the least plausible reason, there is little an armed space marine could use to damage a warship than a nuke or kinetic slug couldn't do better, faster, cheaper and without danger human life (other than the humans in the ship you shot at, obviously). If, at the end of the space battle, the enemy ship is too damaged to repel boarding pods, it can't protect itself from other types of weapons either. If you want to destroy the crippled enemy just spare one more round and close the deal, or paraphrase Eli Wallach: "If you want to shot, shot! Don’t board!"
Stealth boarding for destruction purpose also doesn't make sense, if a ship can close the distance to its enemy undetected it can also leave without notice. If the ship can latch itself to the enemy, it could also latch a remote detonate nuke to the enemy ship body and sneakily get out of the blast radius before pushing the bottom. Second reason is to cripple the enemy ship without destroying it and/or kill its crew. If for whatever reasons the objective is to damage enemy ship so it couldn't fight or change trajectory, it is possible to do so: damaging the engine heat radiators or puncturing propellant tank etc. None of those methods need any boarding parties involved. If the enemy ship could defended itself from boarding pods it isn't crippled enough and required more shots to pound it to dust and if it is so damaged it can't stop boarding pods that ship could be marked as disabled and mission accomplish, and in such case why sent anyone there?
If a stealth ship objectives is disabling the enemy it could do so by placing small explosive charges instead of a big nuke next to the enemy ship's crucial parts before sneak out, achieving the objective without messy boarding.
The third reason is to grab hold on the ship itself or something valuable the ship carries, be it may some important HVT or data in the ship's memory banks (has seen in the Wing Commander film), but all boiled down to this: the ship should not be harm (too much) and someone have to board into it to retrieve that something or someone. The problem begins as the first major step prior to boarding is crippling the target so it couldn't resist the boarding, if the motive for boarding is the value of the boarded ship and the boarder value the ship more than its scrap metal price any damage inflicted to the target to make boarding possible also diminish the target value and the justification for boarding in the first place.
Also, if the ship crew is dedicated to defend whatever the boarder desire and ready to fight to the last man standing and  they will not hesitate to push the self-destructed bottom to take the boarding team down with them; depriving them of their prize. No matter how fast and efficient your boarding party is - you will never outrun someone hand to the red bottom. And of course, some of the potential boarder's prizes could be eliminated without blowing your own ship: shot the hostages or prisoners; delete the top secret data from the computer memory and such.
Last motive for space boarding is tidally locked to the third method of boarding. Stealth in space is almost impossible, everyone sees everyone… up to a point or more accurate up to a ship hull. Studying ship engine output emissions will reveal the engine thrust and couple with the ship acceleration reveal the ship approximate mass. That data for itself is useless; a space hauler might carry its declared cargo of iron ore or weapon grade Uranium. The properties of inanimate cargo are difficult to tell from a far and when it comes down to the identity of the people on board or their motives, save some magic Star Trek sensors the content of a spaceship could be a mystery unless it will be boarded and inspect. A space fleet place a blockade on enemy planet or space station might allowed some humanitarian aid arrived to that planet or station but need to block any weapon or troops shipments, without a boarding team inspecting the vessel there will be no way to tell. Atomic Rocket has a great webpage devoted to future quasi-military organizations, the outer space equivalents to coast guard, customs, etc. All basically relays on boarding civilian ships for search and inspection, similar to modern coast guard day-job activity.
That is the last method of boarding, the or-else approach, and armed spaceship part of “the authorities” either standard military or quasi-military is in the interest of board and inspect a civilian vessel. The armed spaceship contact the civilian one and demand, politely first and shot across the bow if needed, that the civics are to be boarded and resistance is futile at best or disastrous at worst. Such or-else scenarios are the most plausible spaceborne boarding might take, when two ships one outgun and out-maneuvering the other and by threat of brute force convey the would be boarded ship to match trajectories and quietly let a space equivalent of ship boat to dock to the airlock and allow the boarding party enter in.
Such party ought to be armed, if a ship dispatch men to examine a ship is suspected of been hijacked which its passengers are hostages sending those men unarmed might confirm that suspect by providing the hijacker/s with additional hostages and a fully fueled runway shuttle. Even if the ship captain and crew cooperate at (ship mounted) gun point they might play with the idea of taking the boarding party members hostages and negotiate with the sending ship for their release if the think the boarder ship captain value his people life high enough. A gun must be holster to every member of the party to remind the boarded ship crew and passengers who's the boss and a peaceful corporate with the law and author is preferable. In such circumstances, a weapon designed to operate in spaceship pressurized cabins is desire as the boarder don't want to inflict any unnecessary damage to the ship and any non-involved bystander.
Other Potential Users of Pressurized Environments Firearms

Star/Space Marshals
The future equivalent of modern time sky and air marshals, the Star Marshals or Space Marshals will board a civilian spaceliners in plainclothes disguised as regular passenger or crew member to deter spacejackers and if needed, shoot down any hijack attempt. These Space Marshals “guns” will likely be similar those of today's Marshal as well, being a compact concealed handgun with its ammunition will selected to minimize the danger to the crew, passengers and the expensive vessel.

Security and Military Police
Spaceships, space stations, colonies & mining operation bases; all needs some level of armed security force to keep the law and order in check. Even military installations like ships, stations and bases need military police to enforce the order and break all those bar fights between officers. In most cases, those guns will be holstered and carry openly to recognized the man or woman as a member the local law enforcement at the scene and insure cooperation. In some cases, a luxury cruise spaceship for example, the guns will be stored in ship's vault like in modern cruise ship only to be issued to trained crew members in emergency or when Mangalores attack. 

Starjackers and Pirates
The evildoers of the future will their enjoy piece of the action with such purposely build PHF as those guns will enable them to control over (hopefully for them) unarmed crew and passengers of civilians spaceships without endangering their prize ship and hostages, not to mention the shooter’s own life. In the case of starjackers, those guns ought to be easily concealable and able to pass under the scrutiny of the sensors of spaceport security if the hijackers hope to board with the guns in their possession. In case of space pirates, if someone built his universe (like Leiji Matsumoto) in which the common recognized wet navy piracy could exist in outer space those pirates boarding tactics will be similar to the general boarding tactics discussed above and similarly the firearms those pirates boarding teams will likely be similar too.             

Interstellar Repo Men
Many of the advocates of space conquest and colonization, me included, believe that a true human presence in space will be achieved by embracing the principles of the free-market system and the pursuit of wealth. Private companies like Elon Musk's SpaceX and others lowing launch cost and open the door to private companies and individual rushing up to make their lucky strike. In such environment, some of the least pleasant practices of Terra might export to the stars as well. Say you are an individual or part of a small group in the interest of buying your first used spaceship to head on your way to get rich or die trying. Maybe you part of bunch of miners buying a prospecting ship to find that motherload ore deposit in the asteroids belt or maybe half of Maw & Paw business plan on open a hot-dog stand to serve the Mars colonists. Your group don't have enough cash to buy your dream spaceship, what can you do?
Enter the loaner, ranging from respectable bank to back alley loan sharks. There will be those, how are ready to temporary add their money to close that gap between what cash you have and the amount you need, you will return that sum of money with interest cause the loaner is like you… in the business of making money or he’ll break your legs.
Of course, the loaner isn't fond of losing either and that what new businesses and entrepreneurs are best at, most businesses fails and they can't or won't want to pay the lander to repay the loan. This futuristic space loaner, like his counterparts back on Earth, have a way around loses.
When the loan is done, the spaceship will be mortgage and serve as collateral in case of borrower defaults. If the borrower foreclosure, the ship will be repossess and sold by the loaner and if the mortgage is recourse debt type and the collateral sell does not cover the full value of the defaulted amount the borrower is now a debt slave, if not the borrower is “free” to try hitchhike his/her way back home as he or she rot as lurker in the slums sections of the space station. Given such lovely options, some borrowers would simply not turned their ship-home and livelihood back for repossession, but rather turn their transponder beacon off and giving the loaner run for their money out in the black.
For such case,s there are professionals for that task as well: the repossesses or Repo-man. These are the kind who take the efforts to go out and capturing the ship and if possible, its owner and bring them back to the loaner. Repos could be company employees or independent contractor hired by the loaner. Capturing the ship intact is prime objective for the repo-man as the loaner is interest in the ship aftermarket value and pays the repo fixed percentage of the collateral price. There may be ways to kill the borrower, without devalue the collateral, like enhance radiation bomb (aka neutron bombs) or particles beam that will dose the owner, cause he or she to die slowly while the ship hull slowly cool off radiation. Problem is that generally more trouble than it worth. Even if authorities are OK with civilian vessels are armed with death ray and N-bombs, which the likely wouldn't the dying owner of the ship can easily explode his ship to save himself from the slow agony radiation sickness and to have the last laugh as the repo watch his prize blows. A worst scenario is that the owner booby traps their ship to blow up when the landing party break in to the reclaim the collateral taking the prize and the landing team.
A debt defaulter might have the bright idea to avoid the repo ship and the mistakable notion that the repo can't do shit to the capture the ship without damaging the repo reward but that ain't so, there is a little thing that called “reputation”, a loaner might offer the repo a payment for blowing the collateral and the debt runner to dither future potential runner from giving the repos hard work. So, the foreclosed spaceship is going to be boarded similar to the or-else method described above and like the case of inspection boarding the repo boarding party will pack firearms to bring the owner or passengers into submission and cooperation with the repos.

Bounty Hunters
There are many similarities between repo-man and bounty hunters (we don’t need their scum!), both are payed to track and hunt their prize and bring it back with little harm as possible, preferably alive (no disintegrations!). The boundaries between the repos and bounty hunters blur if the debt defaulter sigh a recourse mortgage then the loaner wants both the collateral and borrower back intact as the ship resold in the repossession yard and the borrower have to find somehow a way to pay the rest of the loan. In any case, the bounty hunter ship like the repo ship method of operation is to force the target ship to allow a boarding party to board the ship and capture the target.
Explosive Decompression Myth in Popular Media
Tracking the origin of a common misconception or trope is generally not an easy task. Not so in the case of the case of explosive decompression, its potential causes and its outcomes. In 1964, Goldfinger, the epic third movie of the James Bond series (and one of the best in the entire series), hit the cinemas and it became a major cultural and financial successes. Two scenes from that memorable film gave birth to the airplane (and later spaceship) explosive decompression myth. The first occur when Mr. Bond is held at gun point by Pussy Galore in mid-flight, Bond point out that given the fire power of Ms. Galore's Smith & Wesson any bullet fired will go through him and the fuselage "like a blowtorch through butter" and as result "The cabin will depressurize and we'll be sucked into outer space together". The second occur at the movie climax when Bond and Goldfinger wrestling, with Goldfinger holding a gold-plated revolver and in the middle of the two men fight over the gun it fired and the bullet break one of the plane windows. Just as James warn Pussy earlier the rapid depressurized suck out the plane interior through the small window, James is manage to firm hold some of the plane's chairs but Goldfinger, despite his considerable weight, is lifted by the strong sucking and thrown against the window, after a short dramatic pause where Goldfinger's girth plugging the hole he been pressured out to “outer space”. The movie Goldfinger is the sole responsible for that engraved explosive decompression trope and it span and repeated endlessly afterward. The question then becomes is where the movie screen writers got their idea from?
Naturally, one need not look further than Ian Fleming's original novel Goldfinger for answers, the novel publish in 1959 and indeed, the fatal depressurized scene appear there, too. The details are a bit different though, when held on a plane by Oddjob, Goldfinger's Korean handyman, not at gun point but by Oddjob shear strength and toughness Bond contemplate how he could upper handed Oddjob. Bond has no weapon, save the small spring dagger concealed in his boot. Bond remembered an incident were a passenger were blown out of airliner window at 18,000 feet above Persia (now present day Iran) and that in the press conference it was claimed that the poor soul was “sucked out to outer space”. Bond use his small dagger to tear a hole in the window next to Oddjob not before he himself strap in, resulting in Oddjob thrown out of his chair and out of the plane in a rather dramatic fashion. Seem like a pure fantasy, but such an incident did actually happened.
On April 21, 1957 on an Air France Super Constellation flight from Tehran to Istanbul (not Constantinople) an 31 years old American name Jack Rodney Nash, who sat in the window seat, disappeared into the night as the window glass next to him shattered. According to some accounts Nash slept with his head lean against the window when it breaks. Combining with the fact that the seat was near the emergency door and those door's windows tend to be larger than regular plane windows all hint that Nash involuntary exit of the aircraft was more falling and pull of the air moving rather than “sucked out” via the pressure imbalance, but the newspapers did use the term of “sucked” and “outer space”. Fleming, who read those news reports incorporate the actual event into his novel and thus, the myth was born. 

Firearms and Cartridges of Submarine Crews
There are many parallels and similarities between spaceships and submarines; prime among those is the enclosed pressurized environments both kinds of vehicles contain. There is one major difference between those two types, a spaceship have to hold maximum of 1Atm of inner pressure against the vacuum of space, when a submarine is squeeze inward by water pressure of multi-Atmospheres. If the submerge vehicle use regular air mixture and not saturated atmosphere mixture it is the job of the sub's pressure hull to shield the vessel and crew from implosion. And it much worse than just the absolute pressure difference that a sub have to holds compere to a spaceship, the submarine pressure hull loaded with inward force from all directions face the danger of catastrophic buckling, if such thing occur the sub will implode in a mere seconds, the crew won't have the time a spaceship's crew have to take actions to save their live or the craft.
Luckily, the engineering constrains that dictates a thick and sturdy hull that handle the outside pressure can basically shrug of most of small arms bullets without harm. Nowadays, at least from the available information about US Navy submarines, the subs' crew carry various firearms including pistols, SMG & shotguns, for the intended purpose that is NOT to repel boarders or the arm the crew for boarding enemy submarines either or fighting off the kraken…such scenarios are nigh impossible.
Instead the weapons are stored in the sub armory vault and are used to arm the crew when the sub is docked in the harbor, it is the duty of sub crew to guard the submarine when enter, departure and docked in the harbor from any hostile. Another fairly bizarre armament the US subs carries in their armory vaults is older long guns in full power cartridges such as the M1 Garand & M14. It almost like the crew of the submarine go out hunting or something...Well, sort of hunting, accidentally in mid mission the crew enjoy a surface leave – the sub surface in the middle of the sea or break the ice in the North Pole and let the crew members to stretch their legs and breathe fresh air. If the sub surface in the middle of the sea the crew members could jump in for a swim, if it surface the ice for some running and games on the open ice fields. Both cases on the sub watch-tower stands one submariner with the scooped rifle and search for predators around who feels hungry for some Navy snacks, in the mid-sea it is sharks and polar bears in the poles.

Designing the Perfect PEF
Designing one “perfect” firearm to match the many different conditions and circumstances a shooter/warfighter could face within pressurize arenas is not an easy task and it a great deal a game of compromise between contradicting requirements and specs. As mention in the previous segments of the article, this boils down to a revolver platform. It could be used one handed like any handgun which suits perfectly any CQC situation, especially when fighting in zero-g where it beneficial to have one freed hand to grab a handle or ladder to fix the shooter leaning close to the wall. A revolver can clear dud rounds single handed unlike autoloader, it won't spew empty cases after each shot- only when it time to reload the cylinder.
Since revolvers cycle manually with trigger pulls, the cylinder is indifferent to chamber pressures and could be loaded with wide variety of ordnance various from anti-riots rubber bullets to armor piercing provide greater versatility in different situations and conditions.
Contrary to common believe, it is possible to suppress revolver if a proper gas seal is archived between the cylinder and barrel (known as 'cylinder gap') as in the case of the Russian Nagant M1895 revolver. Another option are revolvers designed for totally enclose piston cartridges. All those techniques used for silenced a revolver could be used to prevent cabin air contamination.
One mostly unknown revolver concept that may be seemly fit for PEF is the Cobray Pocket Friend revolver, a piece of crap gun that nevertheless has an intriguing layout. The revolver is a twin barrel over and under gun, the lower barrel chamber for 22LR and aligned with the lower chamber in the cylinder at 6 o'clock, the upper barrel chamber for .38 ACP and aligned with the upper chamber in the cylinder at 12 o'clock. The gun was sold with two cylinders, the one chamber for .38 ACP had three chambers and the one chamber for 22LR had 5. Both cylinders had a matching curved grooved on the cylinder curvature.
The revolver was double action trigger, per each pull of the trigger the cylinder rotate 120 degrees in the case of the .38 cylinder and 72 degrees in the case of the 22 cylinder. The doubled firing pin hummer hit both cylinders in the 6 and 12 o'clock positions but hit and ignite the right cartridge only when it aligned with it matching barrel. The Cobray is a break open revolver with swappable cylinders, unfortunately the removal and replacement of cylinders is anything but fast, and there were only those two cylinders supplied with the gun. A future design focus on fast ejection of spent cylinder when break open and easy insert of fresh cylinder combined with Shields' preloaded dispensable cylinders could results with the most versatile revolver possible, a handgun that can fire a range of various ammo types in two separate calibers and with the ability to be rapidly switched from one type of ammunition to another with mere swap of the cylinder.           

This is the Outer Space Future – Where is my Ray-Gun?
Some readers might object to the exclusion of Directed-Energy Weapon (DEW) options when designing my perfect PEF and it sure it is odd that any future scenario where deep manned space flight is ongoing and there is human presence off-world exist that the preferred gun of choice to those spaceship boarders are confided to old wheel guns, not so different from their ancestors of the Wild West of beloved Terra. Why an old technology to my mind more likely to dominate the highest frontier at the expense of modern or futurist firearms?

Personal Bias
I ain't gonna lie; I love the aesthetics of old lever action repeaters and revolvers. Something about the manual cycling of the gun have the feeling of more real and intimate connection between the flesh and the steel that the fancy autoloaders lacks. Those guns were also the guns used by lawmen and criminals, the hardened settlers and Native Americans at the conquest of the American West Frontier and I really like the symbolic correlation between the future conquests of space (the last frontier) to the American frontier of the past. Placing a revolvers in the hands of the pioneers who will step out to the stars to make them their own is a much appealing move.

Not all Technologies Scale Down Well
One strong objection to the rejection of DEW is the claim that any future civilian capable of harness the energies required for powering the interplanetary or interstellar spaceships will surely be away pass the weak chemical reaction driven projectile guns of the past in favor of some sort of personal energy weapon. That, however, is a false argument that doesn't consider one key aspect – some technologies are difficult or impossible to scale down from the spaceship level to the compact handgun size. Consider a modern example of nuclear submarine, its power source is the most advanced and compact nuclear electrical power plant that physics and engineering could produce.
However, the officer-in-charge of running the reactor (or 'Nuke' as he or she is called in the US Navy), if armed, would they be armed with plain pistol? Such pistol would most likely patterned after the long serving Colt M1911 .45 pistol or the M9 9mm, a century old gun layout. Its ammo are metallic cartridges, similar in nature to mid-19th century ancestors, which contains gunpowder not so different than the black powder the Chinese used to repel the Mongols with. Why the 'Nuke' not carry an atomic blaster? Thing is that atomic energy doesn't scale down too well, a nuclear reactor is run around the critical mass of the reactor's Uranium pile, reduce the fuel mass by half won't cut the reactor power by mass but simply cut off the nuclear process all together. And there is the shielding concerned of placing enough thickness of dense mass between the fuel and the user, easy to achieve with large reactor as the power output is increase by the cube law while the shielding mass only increase by the square law. Bottom line – even if you are stationed on an atomic spaceship with cutting-edge nuclear thermal rocket engines, that doesn't mean you could holster a ray gun to your belt.

If It's Not Broken…
The principle of KISS (Keep It Simple Stupid) is to keep in mind whenever speculated and extrapolating about future technologies, slow and steady do win races. Many of the concepts we been examine in this article points towards underpowered guns and ammunition as the best choice to those who will carry arms indoors, when common gunpowder is more than enough to tackle threats and not endangering the bystanders or the vessel/station there is no justification to pour in R&D founds to crank up anything as outlandish as a blaster. 
Examples of Pressurize Environments Firearms Examples in Sci-Fi

Mr. Garibaldi’s .38 Revolver from Babylon 5 Episode “Grey 17 is missing”
In the Babylon 5 ‘verse there are no slug throwers in sight, all of the guns are plasma pistols or rifles. In 1996 episode "Grey 17 is missing (3x19)", the rationale behind the EarthForce decision to dump old fashion firearms and replace than with DEW is explain by none other than Michael Garibaldi.
Shortly after the station cut its ties with Earth and the Clark Government, Zack Allan noticed Garibaldi marveling his grandmother's Smith & Wesson. 38 Caliber revolver. Allan apparently never saw such antiquity outside of museums and Garibaldi schools Allan that EarthForce preferred the PPGs because those kills by "burn flesh" and won't punch a hole in the spaceships' pressurized cabins. According to Garibaldi, back on Earth, slug throwers are still in use for private security and practice shooting. It is also noted that although the PPGs of Garibaldi and other B5 security members are DEWs their structure and appearance is more street cop service revolver style, a fresh air after the Star Trek sanitized Phaser "Dust Buster" layout.

The TR-116 Rifle from ST: DS9 Episode  "Field of Fire"
In the Star Trek universe, both artificial energy damping fields and natural radiogenic particle environments are disruptive to the function of phasers. To allow its members to operate and fight in such circumstances, Starfleet R&D developed both the TR-116 rifle and later the regenerative phaser. The TR-116 is a rare example of chemically propelled slugthrower for Star Trek, the bullets were made of Tritanium, a fictional metal that been used to build from most of the Federation starships. The TR-116 were rejected in favor of the regenerative phaser which only mention but never seen on screen. 

The Lack of Slug-Throwers in the Star Wars Universe
Many have question the lack of bullets and normal guns in the Star Wars universe, especially consider how lousy those blasters everyone carry seems to be. Those blasted things can't hit anything, the “laser” bolts they fires race to the target slower than a primitive arrow, revealed the shooter where about like tracer and so on. Why the uber advanced species and civilizations of the SW galaxy do not use good old sluggers?! One non-canon fans theory is that, as the case with B5, the various species and societies of SW found that bullets are a hazard to all of the dwellers of the pressurized spaceships and habitats and settled with the blasters which apparently won't danger the cabins. I wonder how Jedi would fare against a hail of bullets?

The Accident with the Hadley’s Hope Weyland-Yutani Atmospheric Processor from ALIENS
The Atmospheric Processor from 1986’s ALIENS presents a unique example of the dangers of using and applying inappropriate ammo in the wrong environment. In an ironic twist, the processor whose purpose is process and convert unbreathable atmospheres of alien worlds to regular good Terran atmospheric standard air and eliminating the need in pressurize cabins is the victim of over-penetration ammunition.
When a platoon of Colonial Marines are dispatch to investigate the radio silence of a colony of Hadley's Hope on LV-426, they found out that the colony was overrun, but found no dead bodies to tell about the event. The Marines tracked the transponder beacons every colonist carry and find that the missing colonist are all gathered inside of the processor, not knowing that the processor was reclaim by the Xenomorph queen and transformed to a Xeno hive as the Marines steps into the processor.
When Ripley point out to the Lieutenant that the Marines' 10mm explosive-tip bullets could seriously damage the processor's cooling pipes that cool the processor's fusion reactor he order sergeant Apone to take his soldiers' pulse units from their M41A1 rifles and M56 smartguns and switch to flamethrowers instead. Both Vasquez and Drake, the M56 gunners, slip in a replacing pulse unit into their guns that they kept hidden in their pouch. When the Xenos assault the Marines, both Vasquez and Drake spray the Xenos with hot loads of 10mm bullets, taking a number of Xenos down, but in doing that damaging the reactor cooling system and set the time counting down to the processor nuclear explosion that would cover an area the size of Nebraska. 

The Federal Marshal Browning 2000 shotguns from OUTLAND
In the mining outpost of Con-Am 27 on the violent moon of Jupiter, there are no other firearms beside shotguns. The outpost Federal Marshals carries sawed off 12 gauge Browning 2000 shotguns and even the hitmen sent to hunt and silence Marshal O'Niel are issued with scoped version of the Browning 2000. The reason that the director, Peter Hyams, equips the Marshals and hitmen of the far-future with simple shotgun isn't a secret. The movie was set as a “space western” theme that liberally borrowed many themes from classic Western movies like High Noon. And if one wants a Western, you ought to have either revolver or shotgun or both.
In-universe explanation is that in the universe of Outland where vacuum cause humans to instantly pop like party balloons it is wise not to have any gun with capability to drill holes and let the evil-evil vacuum enter in. In one incident, when one of the two hitmen where drawn by spacesuited O'Neil to fire throw the greenhouse glass the shot left a single big hole, evidently caused by solid slug ammunition. The hitman didn't live long to regret his ammunition preference. The Outland novelization providers further detailed about those future shotguns. Those guns are similar to modern shotguns but have variable muzzle velocity selector enable the user to set the desirable muzzle velocity and penetration capability needed for the job.     

The Fall Train from Total Recall (2012)
The 2012 remake to 1990 Schwarzenegger movie feature a unique method of transportation between the two left reminisce of human civilization, a gravity train connects the British Islands with Australia via a tunnel that going way down into Earth mantle grazing the core. The Fall, as this train is called, is simply dropped at one end and fall down by its weight to the tunnel and Earth other side where it catches again. At the middle of the track when the train is closest to the core the passengers experience zero gravity for a few seconds.
The Fall and its Null G phase are the scene for a dramatic free fall shootout as Douglas Quaid spray bullets at the bad guys he simultaneously propel himself and Melina backward away of danger.
Quaid is using TDI Vector SMG, likely chamber of 45ACP, and holds 25 rounds with the extended magazine. Colin Farrell mass is 80 kg and Jessica Biel is 55Kg (according to Healthy Celeb website). Factoring in 45ACP bullet mass 230gr and nuzzle velocity 255m/s, a full mag damped should propelled the weightless couple to 10.8m/s. this is over simplify calculation neglecting the mass of the gun and ammo as each shot should propel back the yet fired cartridges but in that scene the two seem to driven by the recoil slower than this 10.8m/s. So, I would declare that as at least plausible if you ignore that such off the center of mass recoil should impart the two with both linear velocity and angular velocity make them tumbling in midair. 

The Limited Range Shotguns from The Forever War
In the final campaign of the Forever War at Sade-138, Major William Mandela task force were issue among many other technological marvels of future warfare with shotgun shells contains thousands tiny flechettes that can instantly kills up to range of five meters and turned to harmless vapor at six. It been used for close quarters ranges where the laser-fingers of the power suits are too dangerous to be used. Those shotgun shells are fired from the standard grenade launchers the UNEF soldiers are carry. 

The Robo Ammunition from Seveneves
All that remains of humanity 5000 years into the future are gathered in space stations orbiting Earth. The spacers replace the old bullets with smart robotic bullets called 'roboammo' that if missed the target it decelerate using little parachutes to prevent collateral damage. Those roboammo bullets don't relays on kinetic energy either, to counter any thick clothing or armor the roboammo can cruel and search to find weak points and latch to target deliver electric shock or tranquiller substance to knock off the target without killing him or her.
The Boarding of USS Benedict from ALIENS: Outbreak Dark Horse Comic
The span of time between ALIENS and ALIEN 3, the gap was fitted by Dark Horse Comics’ important follow-up limited Black-&-White series. This told the sad tale of two of the survivors of LV-426 massacre: Newt and Hicks. Due to his personal experience with the Xenos, Hicks is selected as the command staff of a dangerous mission to the Xeno homeworld via the advanced USCMC warship, the Benedict. Hot on the heels of the Benedict is the BioNational corporate ship, the K-104 commander by the psychopathic Massey. Using a traitor, the K-104 overtakes and boards the Colonial Marine vessel. During the briefing, Massey tells the PMCs of the K-104 to use “low-level blasters” for the “soft” targets…like equipment and the crew. He gives the explanation that despite the armored hull, an unlucky shot will rapture the hull. Sadly, Dark Horse Comics retconned this important comic, altering the names of the main characters to not conflict with the events of ALIEN3.

Next Time FWS Armory – Heading to the Black Void…Armed!
A question – what will SpaceX Mars colonists be armed with? A Musk-et! Yeah I know, tumbleweed moment. Regardless, the question of arming Astronauts or Cosmonauts is and will be an issue best think of and prepare for in the here and now. The rigors of outer space, in free fall out of the airlock or on the surface of Mars will stress humans and machinery alike. Designing guns for such daunting battlefields will be the topic of the next FWS Armory article: the EVA Guns!

Next Time on FWS...
In the aftermath of the popularity of Mobile Suit Gundam, came more titles centered around mecha like Super Dimensional Macross and Fang of the Sun Dougram. Each one of the works added more to the sub-genre of mecha and they themselves gave rise to new titles as well. With the success of the Dougram, the creative team and the same studio decided to embark on another wartime mecha anime TV series that became one of the most popular and influencial in anime history: Armored Trooper VOTOMS! In the next installment of Future War Stories of the East, FWS will finally be discussing this much requested title.  


  1. Hi ! I like dropping by your site and read these articles. Always nice to learn a few new things about my favorite topics like Space War (more enjoyable when they're inspired/compared with true life examples and designs) ! Keep it up !

  2. The mention of the Coriolis Effect now has me thinking about throwing knives in space. Really, really bad idea but man, it would look cool lol

    Can tell you put allot of work in this article, good stuff.

  3. Thanks for the post!😊 Wish u can tell us about the handheld XM556 micro gun from Empty Shell and how it becomes the spotlight for Gatling guns!

    1. FWS already have an article about miniguns and rotary cannons:



  4. An interesting article, especially on how the issue of using firearms in an enclosed, pressurized space had already been addressed in the jet age against similar concerns. Especially interesting in the type of engineering and cartridge types that would be plausible for any future Space/Star Marshal on any interplanetary transport spacecrafts. And considering that the most ideal small arms to be used in such an environment being a revolver does harken back to the days of railroad robberies and such. While having a concealed revolver (that would have solved the cylinder gap in the simplest, most economical way possible) and a silencer would be the simplest solution, when it comes to the hearing protection of the Space/Star Marshal, well its either having a collapsible version of those electronic shooting ear muffs that automatically shut off when it detects a loud noise or invest in those encapsulated piston cartridges. And considering that the latter would have up to fifty meters in range according to wikipedia, it would be effective enough since I don't foresee such expansive spaceship interiors in the near future that would need anything with a farther reach. And the basic design of Cobray Pocket Friend, once the bugs have been worked out, would make for an iconic weapon of any future Space/Star Marshal. Might even call such derivatives Colt Shields in my own settings, not unlike the derringers of our own past if one gives it a thought or two.

    While on the subjects of the "or else" option of boarding, it does leave a bit of a pickle for any future counter-terrorist operators if there's no alternative and the idea is to actually keep the hostages alive long enough for rescue. Even if there was a Space/Star Marshal present, if there's enough tangos to exhaust the revolver's limited number of rounds and the rather lengthy process of reloading even if the cylinder can be rapidly replaced, the Marshal's not going to last against all those sharpened plastic knives if that episode of Surviving Disaster is to be believed. Though considering the idea of one-armed shooting with the other hand bracing the body for cover and recoil, it would probably be a good idea to add a trigger guard spur for better handling and accuracy of the style.

    Then again, whose to say that commercial and freight shipping space ships would have as expansive or as sensitive of sensors as their government and military counterparts? I can only imagine the equipment that would be used such would either be bulky or heavy enough to really cut into said spacecraft's payload and would otherwise reduce the PAY portion of the word, and considering that profits of such ventures are done in bulk, would probably ignore such sensor systems and instead go for the bare minimum for interplanetary navigation and orbit-to-orbit docking. In addition to the idea that actual windows would not really be needed on such interplanetary spaceflights, it wouldn't be too implausible for the counter-terrorist unit to employ a hacker to mask the approach of a "stealth" boarding shuttle/pod, especially if there's a distraction to keep the hijackers occupied from the exterior cameras and sensors.

    As for less-than-lethal options, I can't help but imagine "bullet trap" type muzzle attachments to launch such rounds to incapacitate the target down range. It would probably significantly reduce the effective range of enclosed piston cartridge rounds, and probably not an option for Space/Star Marshals, but I can imagine that such range isn't a problem.

    Still, it is something to ponder for near-future scenarios and stories.

  5. A most comprehensive article. Considers many factors that even I never thought of or considered. Most enlightening.