You guys will definitely get a kick out of this one - I got a grenade launcher cup for a SMLE, in this case pictured with my 1943 Ishapore Mk.III*. Really simple design, clamps onto the muzzle and fits a Mills bomb with a gas check plate threaded on (don't have that piece yet) inside the cup. Simply insert the grenade, pull the pin (the cup holds down the safety lever), chamber a grenade launching blank and fire it off. Ranging is controlled by the adjustable gas bleed-off valve at the base of the cup. Effective from 50-200M, introduced midway through WW1 and largely replaced by the 2" light mortar in WW2, except in the Indian Army. I'm obviously not going to screw up my Mills bomb by shooting it, but they can launch tennis balls, so it's time to load up some blanks!