Rifle Grenades

[Legbreaker]

This particular item is British in origin and faded into the background here in Australia at least when the M79 and M203 became relatively widespread. In all my years in the infantry I only saw them once and fired about half a dozen (training) grenades with it.
The gas plug on the L1A1 SLR has to be turned to prevent the gas system operating (ALL of the gas goes out the barrel) and a ballistite round used. One HELL of a lot of recoil - enough to break your thumb if wrapped around the pistol grip! The grenade pin is pulled, butt of the weapon placed into the groin (yup, scary, I know!) and the front/only sight on the adapter raised. Propels the grenade up to about 200 metres from my rather sketchy memory.
The grenade and fin section come apart on hitting the ground, the lever is released and the grenade bounces a bit further on until it explodes. The fin section can be recovered for reuse.
The adapter can also be used to fire other types of projectile and the Australian Navy were using them to shoot lines between ships up until about 2000. The rifle can be fired using normal rounds with the adapter (but not grenade I hope!) in place, but it's a good idea to turn the gas plug back around to the normal position first, otherwise you're left having to recock for every shot. A bayonet cannot be fitted at the same time (the adapter uses the bayonet catch to hold it in place).