Works on the M1 and M1-A as well. Actions are similar. In fact, a similar arrangement will also work on SKS and AK variants as well.
Point of my post was pointing out the "string as the registered machine gun under NFA", not so much the rifle and why the NFA regs are unConstitutional and stupid.
69 posted on 12/10/2020 7:06:55 AM PST by Dead Corpse
(A Psalm in napalm...)