Just built an AR upper is it necessary to head space gauge it?

In general, no. A mil-spec bolt plus middle of the mil-spec head spacing will usually have enough slop to not worry. Head spacing relies on the barrel extension, barrel, and bolt. The mil spec bolts are pretty consistent, and they are barrel extension is set up against guages at the factory. That being said, if you are ordering a tight match barrel, and you are using a bolt that is not mil-spec, you may have some issues. Most of the folks who offer that tight a setup usually offer to sell it with the bolt it was head spaced with for a competitive price on the bolt.

 

If you want to be extra certain, get a go and no-go set and make sure the go goes and the no-go doesn't.

What brands are the upper,barrel and bolt?

In general, no. A mil-spec bolt plus middle of the mil-spec head spacing will usually have enough slop to not worry. Head spacing relies on the barrel extension, barrel, and bolt. The mil spec bolts are pretty consistent, and they are barrel extension is set up against guages at the factory. That being said, if you are ordering a tight match barrel, and you are using a bolt that is not mil-spec, you may have some issues. Most of the folks who offer that tight a setup usually offer to sell it with the bolt it was head spaced with for a competitive price on the bolt.

 

If you want to be extra certain, get a go and no-go set and make sure the go goes and the no-go doesn't.

 

ok good to know. No target shooting, just a 16" that i pieced together for a buddy that im going to give to him as a Birthday present.

 

The upper is a PSA, barrell is off another buddies S&W M&P that was never shot, and i haven't bought the bolt yet looking for a good deal on one

You SHOULD be gtg....But you are mixing different mfgs. So why take a chance. Like stated above get a set of go / no go guages...

ok maybe ill see if anyone on here will lend me a set

huh? Isn't barrel extension on? How do you plan on headspacing it?

 

Mix and match bolts to uppers. It won't matter.

 

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huh? Isn't barrel extension on? How do you plan on headspacing it?

 

Mix and match bolts to uppers. It won't matter.

 

Sent from my DROID4 using Tapatalk 2

 

ok i didnt realize thats how it worked, yes the extension was on already

Good lord my post sounded crack addled. Typing while being repeatedly interrupted is bad.

 

Short sane version:

 

It is headspaced when the extension is put on. The most you can do is verify that your bolt/barrel combo is within spec with a set of go/no-go gauges.

 

If you are going to go that route, google for instructions on checking the headspace on an at-15. The process has some differences to doing a bolt gun.