Questions About Receiver Swap & Head Spacing

[50calshooter]

So I'm working on a new build and I managed to find a factory assembled upper that suits my build. The only parts I'm using is the barrel and bolt carrier group and I'm swapping the receiver out for a different brand which was also dubbed as milspec. The barrel nut/delta ring is being replaced by the nut that came with the new rail.

Question, does head spacing need to be re-checked? I figured no because the receiver really has nothing to do with the equation. The barrel extension would've already been preset with the factory bolt, no?

Probably a dumb question but I figured it's better to ask just in case.

 

[Grizzlypeg]

I recently did the same thing, swapped upper receivers, re-used an existing barrel and bolt group. You are correct that it doesn't alter the headspacing. Mine is functioning as good as ever.

 

[Claven2]

In theory you should always verify headspace when you swap a bolt or bbl, but I've never personally found one to be out of spec after quite a few builds...

I'm sure someone will chime in though saying they have - not all barrel chambers are reamed and set to the extensions equally.

 

[Dsiwy]

I have replaced over a 1000 of C7/C8 barrels YES 1000 "FML lol" I have never seen a headspace issue ever

 

[Urban_Ops]

I usually check it since I have the gauges. But haven't run into a bad one aside from early DPMS stuff.

 

[DaveGP]

If we're talking about swapping an AR upper, why would that have anything to do with affecting headspace??

 

[50calshooter]

If we're talking about swapping an AR upper, why would that have anything to do with affecting headspace??

Well that was my train of thought but I figured it wouldn't hurt to ask just in case I over looked something.

 

[Armedsask]

If built to spec, you never have to head space an AR15. That's the beauty of locking into the barrel and not the receiver.

 

[Lee Enfield]

If built to spec, you never have to head space an AR15. That's the beauty of locking into the barrel and not the receiver.

A standardized barrel extension and standardized bolt design with fairly tight dimensions.