The Firing Line Forums - View Single Post - Need help: identify barrel on Mac10 for correct suppressor

Willie Lowman · December 16, 2011, 11:29 AM

Another half assed explanation...

It's Diameter x T.P.I.

My Ruger is 1/2x28. (half inch diameter threads, 28 turns per inch)

My Sig is 13.5x1 mm (thirteen and a half millimeters diameter, one turn per millimeter)

Also, do not measure from the the outside diameter of the barrel. You measure the O.D. of the threads. I am guessing you have a 9/16x24 threaded barrel. 9/16x24 is a thread pitch used by some manufacturers for .45 acp stuff. My calculator tells me that 9/16 is .5625. If your threads are in fact .61, don't know what it would be.

Hope this helps more than it confuses.

December 16, 2011, 11:29 AM	#4
Willie Lowman Senior Member Join Date: March 5, 2009 Location: Uh-Hi-O Posts: 3,006	Another half assed explanation... It's Diameter x T.P.I. My Ruger is 1/2x28. (half inch diameter threads, 28 turns per inch) My Sig is 13.5x1 mm (thirteen and a half millimeters diameter, one turn per millimeter) Also, do not measure from the the outside diameter of the barrel. You measure the O.D. of the threads. I am guessing you have a 9/16x24 threaded barrel. 9/16x24 is a thread pitch used by some manufacturers for .45 acp stuff. My calculator tells me that 9/16 is .5625. If your threads are in fact .61, don't know what it would be. Hope this helps more than it confuses. __________________ "9mm has a very long history of being a pointy little bullet moving quickly" --Sevens Last edited by Willie Lowman; December 16, 2011 at 11:48 AM.