Locking lugs and barrel extensions

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[ARCHIVED THREAD] - Locking lugs and barrel extensions

Posted: 10/26/2004 10:34:35 AM EDT

Hi, I'm new here. I have a few questions about the AR-15 barrels that I can't seem to find via the search function, and I don't really want to pull my barrel to find out.

I'm looking for info on the thread diameter and pitch used on the chamber end of the barrel to attach the barrel extension (with the locking lugs)

Also I'm looking to find out the diameter of the barrel extension where it slides into the upper receiver. maybe one of you guys has an extra barrel or upper laying around you could measure with a caliper.

Posted: 10/26/2004 10:52:45 PM EDT

[#1]

anyone?

Posted: 10/27/2004 2:47:20 PM EDT

[#2]

.810x16 threads on a .620 shank. Extension diameter: Colt 1.000, DPMS .999.

Posted: 10/27/2004 2:49:05 PM EDT

[#3]

Quoted:
Maybe one of you guys has an extra barrel or upper laying around you could measure with a caliper.

Nobody here has extra barrels hanging around. What do you think this is....................

. I haven't measured one lately but the above numbers look close. Maybe I'll go check..................

Posted: 10/27/2004 4:33:20 PM EDT

[#4]

I have a couple of barrels the barrel extensions are removed they are used military ones intersted ?
$25.00 shipped to you , now befor you get all hyped up these barrels NEED WORK ! if you want to use them you will have to have a lathe and a lot of time it is a real pain in the A _ _ to index the barrel extensions to the gas port and get it right if you can not do this your just throwing you $$ away

Posted: 10/28/2004 10:08:24 AM EDT

[#5]

Thanks for the help guys!

gunrunner1000,
I'm actually looking for a barrel extension or two and the barrel nuts to go with them. I have a barrel that I want to use on an AR-15 caliber conversion upper.

Posted: 10/28/2004 2:13:01 PM EDT

[#6]

Ah, a do it yourselfer. Welcome. Here's a little more info that applies to the .556 chamber. The bevel leading into the chamber is 29-30 degrees and has an outer diameter of .570-.650. You need .1 thread relief at the barrel shoulder.

Finish chamber depth can be measured by putting the gauge in the chamber and screwing the extension on with the stripped bolt in place. The gap between the barrel shoulder and the extension is measured with feeler gauges and that's how much farther the chamber has to be cut - add a little for crush.

Posted: 10/28/2004 3:28:24 PM EDT

[#7]

have all parts in stock give me an email [email protected]

Posted: 10/28/2004 5:46:10 PM EDT

[#8]

Thanks for the extra info olephart. I want to do a few upper conversions, and it seems that the best way is to just get the parts and try it.

Gunrunner1000, I sent you an E-mail.

[ARCHIVED THREAD] - Locking lugs and barrel extensions

AR-15 » Build It Yourself

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