Since the 12th century, humans have been using gunpowder to propel metal projectiles into the bodies of their enemies. Prior to this invention of gunpowder, around the 11th century, human used bows and slings to kill their enemy at a range. Now, that mankind is at the dawn of the 21st century, it seems that the traditional firearm is here to stay. However, there was an active attempt in the 1980's to bring new firearms technology to the battlefield over the traditional firearms of that day. One of these projects was the Hecker & Koch caseless G11 rifle, and the other was headed by the US Army. Between 1986 and 1990, the United States Army held the Advanced Combat Rifle Program (ACRP) to explore possible replacements for the M16A2 using next generation firearm technology. The requirement was for a 100% improvement over the (then) Colt M16A2 platform, because the Army's own infantry school felt the M16 had already at an apex. This blogpost originated way back in 2008, when I was working on my first military science fiction novel, and I was interested in keeping the book as real as possible. I quickly decided on using more conventional weapons, but wanted them with a next-gen twist. This sparked research, but I was unable to locate much in the way of a resource for the near future of the classic bullet and led to this blogpost which has been on the draft slush-pile for three years!
Why We Still Use Bullets and not Beams
Large Caliber Assault Rifles
For as long as I've read guns magazines, there have been the haters of the 5.56mm round, and since the late 1990's, there has a flood of custom produced large caliber cartridges for the AR15 platform. These are rounds like the .50 Beowulf, the .458 SOCOM, and the .450 Bushmaster, and all share were designed to increase the power of the AR-15 assault rifle. This is interesting twist of history, because it was the larger, more powerful rifle cartridges of the 20th century that hindered development of the assault rifle concept. It wasn't until the 3rd Reich developed the intermediate cartridge that the assault rifle was born, and it seems these smaller firearm companies are seemingly turning back the hands of time. Fueling the developing of these powerful cartridges for AR15 is an increase in lethality in a familiar weapons' platform for the shooter. Are these massive rounds the future of the bullet? No really...not a large scale anyways.
The 6.5mm Grendel
Are We Going Back to the 7.62x51mm?
Smaller High Velocity Cartridges
It was believed in the 1980's, that the future of the bullet could be liberating it from its metal casing, and wrapping the bullet in propellant. and causing the bullet to resemble a piece of chewing gum or a leftover clay. This would save weight, and allow the future soldier to hump more ammunition. The closest caseless weaponry ever came to wide-scale approval was in the late 1980's with the West German Army/ H&K G11 project that was nearly the standard rifle of their army.
However, the Wall coming down, unification of the Germany, economic issues caused the cancellation of the G11, and caseless weaponry has remained in the shadows ever since.What the G11 project demonstrated was the strengths and weakness of milspec caseless ammunition. While there is weight saving, higher RPM, and more rounds carried, the ammunition itself is fragile, and prone to cracking. During tests of the G11, the ammunition was the hardest to prefect, and even after years of trial-and-error, the 4.73mm ammo would still crumble like a dry cookie if handled to much. This is a major disadvantage of caseless rounds, today's soldiers do not have to worry about the elements breaking down their ammo, unlike soldiers of the past. If caseless ammunition was adopted on a wide-scale, this could be a concern again. Could there be a future for caseless weaponry? Some believe that caseless guns could enjoy a comeback when there is armed conflict on off-world colonies because caseless weapon can be sealed more than traditional firearms, so that no pesky Lunar or Martian dust gets into the action of the rifle. Is caseless ammunition a good element for a sci-fi work? Yes, if used properly. I included caseless ammunition in my MSF novel Endangered Species (that is at a few publishers at the moment) and I felt it was a good match for the environment.
The 'Duplex' Round
While this sounds great, and the Colt ACR was very similar to the (then) present day M16A2, there was issues. Inaccuracy was the most common issue, and for long-range engagements, beyond 325 meters, the shooter would have to switch to traditional M855 5.56mm NATO ammunition...which would be bitch under combat conditions like we've seen in Iraq. It is likely these issue would have been worse in today's M4 carbines. Given the lack of development of duplex ammunition since the end of the ACRP, it is unlikely that the duplex round is not the future of the bullet. Could the duplex ammunition be a good element for a sci-fi work? Not really, given the weakness of the range and abandonment of the concept, and the rarity of knowledge on the concept. BTW, that oddball rail-rib on the foregrip on the Colt ACR M16 was designed for point-and-shoot concept using iron sights that used the eye's natural abilities.
Cased Telescoped Ammunition (CTA)
Polymer-Cased Ammunition (PCA)
Flechettes are nothing new, shotgun shells have been packed with these nasty little fuckers for years, and from the 1960's onward, they were believed to be the next step in military firearms. During the US Army's ACRP, two separate weapons used carbon steel flechette ammunition: the Steyr ACR and AAI ACR. Similar in design to the AUG bullpup assault rifle, the Steyr ACR fired lightweight plastic telescoped synthetic 5.56mm case flechettes that traveled at 4,757 FPS, where the conventional 5.56mm travels at around 3100 FPS. Unlike the Steyr, AAI's ACR was a more traditional layout, but shared the idea of using the 5.56mm shell for their dart. Despite the similarities between the 5.56mm magazines, the AAI ACR could not accept the M16 mags, and firing traditional 5.56mm ammo would damage the barrel.
The 'Smart' Guided Bullet
Leadless "Green" Bullet
Given the toxic nature of lead-based ammunition and its abilities to containment soil at firing ranges, the US Army is exploring the use of leadless 'green' bullets. This also helps with lead vapor that floats about during indoor shooting. This has been one element to the Army's mission to be more environmental friendly that was undertaken in 1994. These so-called 'green' rounds are a composite of tungsten, tin, and/or zinc fitted within the traditional cooper-jacketed. The goal was to be lead-free by 2005...and they didn't met that. These lead-free ammunition is going to be the future of bullets in the short-term, and would be a good element for a science fiction work.
Magnetically Propelled Bullets
The vintage US Army's ACRP footage