M1 grenade adapter

The M1 grenade projection adapter was an expedient rifle grenade used by the American military in World War II, Korea, and Vietnam. It consisted of an add-on 22 mm stabilizer tube and fins that converted a hand-grenade into a rifle grenade. It supplanted the M17 rifle grenade, and was eventually made obsolete by the 40 mm M79 grenade launcher.^[1]

(From left to right): M1 grenade adapter with Mk.2 fragmentation grenade, M22 smoke rifle grenade with impact fuze (unknown smoke color), M17 fragmentation rifle grenade with impact-fuze, M2 grenade adapter with AN/M8 smoke grenade (red)

The M1 grenade projection adapter was designed to easily convert standard Mk 2 hand grenades into rifle grenades. This was done by inserting a Mk 2 grenade into the prongs while a holder on one of the prongs kept the arming lever from releasing. The unit was then placed on the 22 mm M7 grenade launcher attached to the M1 rifle's muzzle. The user then removed the grenade's safety pin and braced the rifle from a standing or kneeling position. The unit was launched by firing a high-powered blank from the rifle. Inertia caused the holder to shear off in flight, releasing the lever and arming the grenade. The grenade would then explode when its fuse ran out.

Although somewhat clumsy in appearance and operation, the M1 grenade projection adapter was well liked by the troops, who more often than not preferred it to the earlier M17 rifle grenade. The M17 would often fail to detonate if it impacted on sand, water or mud; only solid ground would cause it to detonate.^[2]

Variants

• M1 - four prongs, no base cup, and solid or slotted tailfins. It was designed to launch the Mk 2 fragmentation grenade.
• M1A1 - three prongs, a base cup to secure the grenade, and solid tailfins. It was designed to launch oval-shaped grenades like the M26 fragmentation grenade.
• M1A2 = three prongs, a base cup to secure the grenade, and slotted tailfins. It was an improved version of the M1A1 with a reinforced tube and redesigned tailfins.

Users

•  Philippines - Used by the Philippine Army and Philippine Constabulary during World War II and post war era from 1942 to 1990s.
•  Portugal - Portugal adopted a version of the M1A2 as the Dilagrama m/65 for use with the FN FAL and H&K G3 rifles. They did not need the grenade launcher bracket because it was built into the weapons' muzzle brakes as part of a NATO STANAG requirement.

M2 grenade projection adapter

The M2 chemical grenade projection adapter was designed to launch cylindrical chemical grenades like smoke, white phosphorus, and tear gas. The chemical grenade was inserted into the short prongs on the base disc; a spring-loaded metal collar (called a "set-back band") slid over the middle kept the arming lever from releasing. The unit was then placed on the 22 mm M7 grenade launcher attached to the M1 rifle's muzzle. The user then removed the grenades safety pin and braced the rifle from a standing or kneeling position. The unit was launched by firing a high-powered blank from the rifle. The shock of firing causes the collar to slide off in flight, releasing the lever and arming the grenade.

References