Threads concentric to bore? > CMMG Inc

Posted: 9/16/2008 7:09:46 PM EDT

I am interested in buying an upper with the 14.7" bbl and perm A2. The only thing making me uneasy is not knowing 100% that the permanently attached A2 will be concentric to the bore. I will be running a can on this upper, and thus need it to be squared away. So, my question is are these running concentric, and would a return policy allow me to swap an unfired upper if it turned out not to be?

Posted: 9/16/2008 8:03:45 PM EDT

[#1]

You could consider getting a 16 in and having ADCO chop and thread it for you.

Posted: 9/17/2008 7:13:00 AM EDT

[#2]

Quoted:
You could consider getting a 16 in and having ADCO chop and thread it for you.

+1

There was a detailed write up on it somewhere on the tech forums.

Posted: 9/17/2008 5:25:28 PM EDT

[#3]

Quoted:
You could consider getting a 16 in and having ADCO chop and thread it for you.

I understand that as being an option. But I want to find out if the CMMG barrels are threaded concentric to the bore to avoid an additional $75 expense if I don't need it.

Posted: 9/17/2008 6:06:17 PM EDT

[#4]

Quoted:

Quoted:
You could consider getting a 16 in and having ADCO chop and thread it for you.

I understand that as being an option. But I want to find out if the CMMG barrels are threaded concentric to the bore to avoid an additional $75 expense if I don't need it.

Of course they are threaded to be concentric why would anyone want it not to be?

Posted: 9/17/2008 6:40:07 PM EDT

[#5]

Quoted:
Of course they are threaded to be concentric why would anyone want it not to be?

There are plenty out there that aren't. Have one in my gun safe right now.

Posted: 9/19/2008 10:17:56 AM EDT

[#6]

... are these running concentric, and would a return policy allow me to swap an unfired upper if it turned out not to be?

Well, any reasonable return policy would allow you to return it if the threads were NOT concentric, IMHO.

This seems like pretty basic machining to me, and if muzzle threads are NOT concentric, then what would happen if you replaced the flash hider with a tight compensator? Ka-Boom?

Ben

Posted: 9/19/2008 10:20:58 AM EDT

[#7]

i have 3 CMMG barrels i use a can on, all three are concentric

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[ARCHIVED THREAD] - Threads concentric to bore?

[ARCHIVED THREAD] - Threads concentric to bore?