The DOE Colt Was for Nuke-Plant Guards
Imagine a super-tiny M-16
Often described as the “DOE Colt,” after a 1980s U.S. Department of Energy contract for submachine guns, the R0633 is a nine-by-19-millimeter submachine gun based on the M-16. Colt employees referred to the R0633 as a “briefcase gun.”
The DOE Colt is select-fire, with a three-position selector switch. It’s 21 inches long and has a seven-inch barrel. The tiny submachine gun weighs 5.9 pounds. Its sights are fixed to 50 meters. The R0633 feeds from Uzi-pattern magazines, as all Colt nine-millimeter submachine guns do.
The DOE Colt uses a blowback action, fires from a closed bolt and lacks a forward assist. It also boasts a folding front sight and a collapsible stock. The standard R0633 features a heavy bolt, while the R0633HB uses a hydraulic buffer system.
The prototype featured a one-piece aluminum foreguard. But Colt replaced this with the handguard from the M231 Firing Port Weapon. Likewise, the prototype had ambidextrous controls, but the production model lacks this feature.
The DOE Colt beat out the Heckler & Koch MP5K and equipped guards at Energy Department nuclear power stations. Today the R0633 is extremely rare.