XM148 grenade launcher
Appearance
The XM148 was an experimental grenade launcher manufactured by Colt Firearms during the Vietnam era.
It was designed for installation on M16-type rifles in an underbarrel configuration. The launcher's barrel could swing down to accept a new 40 mm round into the breech. The XM148 was eventually turned down in favor of the M203, which is still the primary grenade launcher used by the US armed forces today.