 The AKS-74U featured an extremely short 8.1" barrel which necessitated redesigning and shortening the gas-piston and integrating front sights onto the gas tube; the Colt Commando was a bit longer, at 11.5".Neither was adopted as standard issue, although the US did later adopt the somewhat-longer M4 carbine, with a 14.5" barrel.By the 1990s, the US had adopted the M4 carbine, a derivative of the M16 family which fired the same 5.56mm cartridge but was lighter and shorter (in overall length and barrel length), resulting in marginally reduced range and power, although offering better mobility and lighter weight to offset the weight of equipment and armor that a modern soldier has to carry.