Send us your barrel and we can thread the tip in front of the massive 7/8x9 threads with a .578 x28 standard .45 acp pistol threads or .30 cal threads of 5/8x24. It will enable you to thread on your .45 acp suppressor or muzzle brake of preference on your Mac or MPA gun. we can also thread the tip of your Mac-10 9mm/M11 9mm barrel in 1/2x28 as well. Please call with questions.
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