OD for FH threads

AR-15 » Build It Yourself

AR Sponsor:

Posted: 11/2/2004 11:14:28 AM EDT

Can someone tell me the OD for the threads on the barrel? I removed the MB off a barrel I have, I don't have a FH on hand to try, the reading I get with my caliper is 0.600 inches. Does this seem right for the 1/2x28 threads? Thanks

Posted: 11/2/2004 12:52:32 PM EDT

[#1]

No, 1/2 inch = .500, which is what (less a thou or 2 for clearance) the outside dia of the thread should be for a 1/2 - 28.

Posted: 11/2/2004 6:32:57 PM EDT

[#2]

I believe .6" will allow you to use a 1/2"-28 threaded flash suppressor, that is to say there is enough 'meat' to allow 1/2"-28 threading.

Posted: 11/2/2004 6:48:21 PM EDT

[#3]

Quoted:
Can someone tell me the OD for the threads on the barrel? I removed the MB off a barrel I have, I don't have a FH on hand to try, the reading I get with my caliper is 0.600 inches. Does this seem right for the 1/2x28 threads? Thanks

If you get the first 5/8" of the barrel turned down on a lathe to 0.500, you can thread it 1/2x28, but then you only have a 0.050" shoulder for the FH, which isn't really enough, IMHO. Does the barrel get bigger behind the the 0.600" section where the MB was located?

Posted: 11/3/2004 4:30:48 AM EDT

[#4]

The barrel goes to 0.732 behind the threads. I emailed Adco to see if they can recut the threads, if not to see if they can cut barrel , thread,and perm attach an A2 to keep it at 16"

Posted: 11/3/2004 4:37:37 AM EDT

[#5]

Quoted:
The barrel goes to 0.732 behind the threads. I emailed Adco to see if they can recut the threads, if not to see if they can cut barrel , thread,and perm attach an A2 to keep it at 16"

Ok, .732 gives a much better shoulder; Adco should have no problems turning/threading it.

Posted: 11/3/2004 11:20:54 AM EDT

[#6]

Text deleted after some reflection!!

[ARCHIVED THREAD] - OD for FH threads

AR-15 » Build It Yourself

AR Sponsor:

Win a FREE Membership!

Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!

You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.

Warning

Confirm Action

About AR15.COM

Stay Connected

Newsletter

Contact Us