Stick

I tried with a K-VAR kit some years ago, but had too much trouble finding a route for the trigger link past the magazine. But that was the only real hang-up. Clearance between the heel of the pistol grip and the front of the magazine base was close, but that could be fixed with a Dremel. Worth looking at if you're handy and don't mind risking your face.

I'll take it if it has plain sights, not rib-style.