M1
4 prong
solid fins
M1
4 prong
cut out fins
M1a1
3 prong
solid fins
M1a2
3 prong
solid fins
M1a2
3 prong
cut out fins
The M1 rifle grenade adapters were made to hold the MKII style of fragmentation grenade. The adapters were designed to replace the M17 rifle grenade. There are a few mojor differenced between them such as the number of prongs to hold the grenade, a small cup placed under the grenade on the M1a2 series, and the cunstruction of the fins.
T2e1
3 prong
cut out fins
M2
3 prong
solid fins
M2a1 3 prong cut out fins
The M2 grenade adapters were designed to carry any chemical, smoke, or cannister style grenade.