US Army
This is a very unusual full powered battle rifle with an impossibly short barrel. Find out how this US Army prototype M4 replacement is able to achieve a high muzzle velocity in this video. It fires the very high powered 68 x 51 mm cartridge from the shortest barrel configuration that I’ve ever seen for this kind of weapon. Normally this kind of large caliber is reserved for barrels longer than at least 13 inches so that it can have enough muzzle velocity to hit targets at 800 meters.#
Credit
Task & Purpose
