Ar headspacing problem

[Paul053]

I heloed buy a friend who's new to ars a brand new direct impingement pws upper. A no name brand new bcg came with thr purchase. He came over to get it head spaced and we ran into a problem. The bolt would not close on a go guage. Everything was dry so i thought maybe a little lube would help. No dice. So carefully i closed it on a live round. It did and ejected fine with no abnormal markings on thr brass. Any clue to the issue?

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[ar15barrels]

Any clue to the issue?

Headspace is short.
Following the Army manual, replace the bolt first.
If that does not solve it, replace the barrel.

It's common for plated bolts to cause headspace to fail on the short side.
If it has one of those nickel-plated needs-no-oil wonder bolts, try a parkerized bolt and see if the problem goes away.

[Paul053]

It is a parkerized bolt

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[ar15barrels]

It is a parkerized bolt

Try a different bolt.
If that does not fix it, then it's probably the barrel.

What go gauge are you using?

[Paul053]

The brand you recommended a while back when I asked which guage to get.

[Paul053]

That sucks if it's the barrel. I told my buddy that it was a good buy, 500 bucks for a pws upper and bcg. Come to think if it I tried a different bcg and it didn't fit either.

[Devilmonkey89]

That sucks if it's the barrel. I told my buddy that it was a good buy, 500 bucks for a pws upper and bcg. Come to think if it I tried a different bcg and it didn't fit either.

It might have been cheap for a reason.... Sucks.

[ar15barrels]

The brand you recommended a while back when I asked which guage to get.

What SPECIFIC gauge?
What is the dimension on the gauge?

[baih777]

Take it to Randall. He will make it work.

[machrono]

+1 for Randall, problem solved.

[Paul053]

Forrester 223 rem gauges. Could this be why they wont close because i used them in a 556 chamber?

Actually just checked Forresters page and they say 556 nato needs a special longer headspace guage.


I think i bought mine through brownells so will be returning them.

On second thought i used them on my rifle that also has a 556 nato chamber (bcm lightweight barrel) and it closed fine on the go guage. What does that mean?

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[ar15barrels]

Forrester 223 rem gauges. Could this be why they wont close because i used them in a 556 chamber?

Actually just checked Forresters page and they say 556 nato needs a special longer headspace guage.

On second thought i used them on my rifle that also has a 556 nato chamber (bcm lightweight barrel) and it closed fine on the go guage. What does that mean?

http://ar15barrels.com/data/headspace.pdf

223 and 5.56 should BOTH fit the same GO gauge.
It's the NO-GO and FIELD gauges that are different.

[Paul053]

http://ar15barrels.com/data/headspace.pdf

223 and 5.56 should BOTH fit the same GO gauge.
It's the NO-GO and FIELD gauges that are different.

So im still dealing with either a bolt problem or barrel problem.

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[ar15barrels]

So im still dealing with either a bolt problem or barrel problem.

Just like in post #2 of this thread.

The good news is that short headspace is not unsafe.
As long as the gun chambers ammo, you can shoot it.

The only problem with short headspace is that some ammo (which is on the long end of it's specification) may not chamber easily.
Most ammo is made on the short end of it's specification and would probably fit just fine assuming your chamber is not dramatically short.

[Paul053]

Thanks for your expertise Randall.

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