XM148 Grenade Launcher

The XM148 was an under-barrel 40mm grenade launcher developed by Colt for the M16 rifle during the Vietnam War. Designed as a lightweight alternative to the standalone M79 grenade launcher, it mounted directly beneath the M16's handguard and was fired using a trigger mechanism positioned forward of the rifle's magazine well. The XM148 was a single-shot, break-open weapon that fired the same 40x46mm low-velocity grenades as the M79, giving infantry squads organic grenade capability without requiring a dedicated grenadier. Despite being replaced by the improved M203 in 1969, the XM148 was a pivotal step in the evolution of under-barrel grenade launching systems that are now standard on military rifles worldwide.