Chamber reaming - AR15.COM

Posted: 2/13/2013 6:16:29 PM EDT

Picked up a barrel at a gunshow. Marked 5.56 NATO. Problem is the lugs in the chamber are a bit long not allowing bolt to rotate. Need someone that has the ability to ream it to proper specs. I'm in the Tri Cities, but am open to shipping to a shop for the work. Been trying to find a reamer, none to be found. Plus I've never performed the action before. Any references or leads would be greatl help. Does Rainier Arms do it?

Posted: 2/13/2013 6:54:16 PM EDT

[#1]

do you mean when you put the bolt into the barrel extension the bolt won't turn smoothly?

Posted: 2/13/2013 7:31:21 PM EDT

[#2]

Doesn't rotate at all. Dead heads. The lugs on the bolt does not clear the lugs in the chamber.

Posted: 2/13/2013 8:13:03 PM EDT

[#3]

Quoted:
Doesn't rotate at all. Dead heads. The lugs on the bolt does not clear the lugs in the chamber.

Buy me a 5.56 pacific precision reamer and I will do it.

Posted: 2/13/2013 10:33:04 PM EDT

[#4]

Quoted:

Doesn't rotate at all. Dead heads. The lugs on the bolt does not clear the lugs in the chamber.

If you mean without a cartridge in the chamber then that's not headspace and won't be fixed by a reamer. The gap between the breech end of the barrel and the lugs on the inside of the barrel extension are too close together or the bolt lugs are too thick.

Posted: 2/13/2013 10:40:19 PM EDT

[#5]

Posted: 2/14/2013 4:51:15 AM EDT

[#6]

Quoted:

Quoted:
Doesn't rotate at all. Dead heads. The lugs on the bolt does not clear the lugs in the chamber.

If you mean without a cartridge in the chamber then that's not headspace and won't be fixed by a reamer. The gap between the breech end of the barrel and the lugs on the inside of the barrel extension are too close together or the bolt lugs are too thick.

The bolt was pulled from a functioning rifle. It's the chamber on the barrel. I'll probably end up sending it back and waiting 6 months to get a replacement.

Posted: 2/14/2013 6:52:15 AM EDT

[#7]

Try another bolt

Posted: 2/14/2013 8:19:04 AM EDT

[#8]

Sounds to me like the barrel extension is installed wrong

Posted: 2/14/2013 11:08:12 AM EDT

[#9]

Quoted:

The bolt was pulled from a functioning rifle. It's the chamber on the barrel. I'll probably end up sending it back and waiting 6 months to get a replacement.

That narrows it down but you should try another bolt or two to be safe. If those still don't work then it's not so much the chamber as it is either the barrel extension is mis machined or the threads on the breech end of the barrel are too long.

If it's the extension you're pretty screwed a it would take a bucket of extensions to find another one that will time up correctly.

If it's the barrel threads then a skilled smith can remove the extension, re cut the rear of the barrel to the proper dimension and set the thread distance so that the extension times up again; the latter is the same principle as setting back the barrel on a bolt gun.

You said you could send it back to the maker, so you know the maker?

Posted: 2/14/2013 3:03:05 PM EDT

[#10]

Finally got ahold of the maker. He's sending out a new barrel. He's had 4 out of a batch of 20 come back with chamber issues.

He has contracted a new machine shop from this mishap. He's a small shop trying to break into the industry. I gave him some advise.... Get your spec's in order. Not going last long if you have machined parts coming back at this rate.