The was introduced in 1939 as a grenade launcher for the Type 38 and Type 99 Arisaka rifles.
Design The Type 100 launches standard Type 91 and Type 99 hand-grenades.
The launcher is somewhat unusual in that rather than using the more common cup designs it is a gas trap system, meaning that it incorporates a barrel extension which taps off excess propellant gases to launch the grenade from a cup offset from the barrel.
This has the advantage that standard rifle cartridges could be used along with the standard hand-grenades which simplified logistics, at the expense of increased weight and decreased efficiency.
The effective range is approximately .http://www.lonesentry.com/articles/jp_rifle_grenade/index.html Model 100 Grenade Launcher Produced in Two Types" from Intelligence Bulletin, Dec. 1944
Users
Imperial Japanese Army Imperial Japanese Navy
See also Rifle grenade
References