If you want the flexibility of having both threads of 3/4x10 and 1/2x28 on a side cocking M-11 upper with a scope rail mount, then this is the perfect set up. Barrel has been double threaded and pinned, just slide in your bolt assembly and you are ready to go. Fits M-11 9mm SMG, Semi Auto & MPA Mid sized M-11, does not fit MPA Mini 930..* IN PRODUCTION
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