HelloJohnnyBlade
Requiem in Mortis
It's called the China Lake Grenade Launcher. The EX-41 wasn't produced until twenty years after the original, and unlike the China Lake Launcher, which was actually used, the EX-41 never went beyond prototype (only one was ever made).
They look too similar. Honest mistake. What's the difference in design?
It's rounds were a hybrid of the 40x46mm grenades used in the M203 and such, and the 40x53mm rounds used in the Mk. 19. It also had a 4+1 capacity, rather than the 3+1 of the China Lake Launcher. Beyond that, it's pretty similar.
Like I said, though, only one prototype was ever made. It had too many problems.