AR headspacing question

[superduty]

Guys-

 

I've read online about headspacing an AR  until my eyes bled, but I really cant seem to find a definitive answer on this issue-

 

So, if you are mating a new barrel (20in) to an upper receiver, is it necessary to check headspace?  Some say always, others say

the barrel maufacturer sets the headspace on their end so you just install the barrel and go shoot it.

 

 

BTW, the barrel would be of new manufacture, and the BCG would be one that I already had- what was previously a spare.  I think it came from AIM, if it matters.

 

Thanks-

[gregintenn]

It has been my experience that since the bolt locks into the barrel extension, the barrel/barrel extension assembly should be properly headspaced when you purchase it. Now if you were putting these pieces together yourself, you'd need to check the headspace. If you have any doubt, your local gunsmith should have a set of go/no go gauges with whit he could verify a proper headspace for you for a nominal fee.

[Oh Shoot]

It has been my experience that since the bolt locks into the barrel extension, the barrel/barrel extension assembly should be properly headspaced when you purchase it....

 

Yup, you pretty much have to trust who sells you the barrel and bolt control group. An in spec barrel extension and BCG determines the headspace. And assembling your own barrel extension takes some real equipment and expertise beyond most of us.

 

- OS

[KorbenDallas]

+1 on the go/no go gauges. If you plan on getting more AR15 style rifles or swapping barrels it's fairly easy to check yourself. The gauges are not very expensive and beats going to a gunsmith every time. Check youtube for tutorials.

[Dolomite_supafly]

Swapping barrels between uppers does not affect headspace. Swapping bolts between barrels can but I have never seen swapping bolts cause a problem. I have tons of bolts I swap around all the time. I will say that I do measure my bolts and try to use the "tightest" bolts with the barrels that tend to shoot the best. I have measured bolts that varied .002" but that is well within the tolerances.

 

Any barrel with the extension installed should be safe to shoot with any bolt carrier unless it has a lot of rounds through it.

 

Unless you installed the barrel extension, and drilled the gas port, there is no need to check headspace unless you suspect there is a problem.