Gunsmithing AR15 barrels and headspace

[HotIce]

Is <span style="text-decoration: underline">your own bolt</span> really needed for proper headspace when buying an already chambered, ready to install, barrel?
Krieger tells me that tolerances on bolts are pretty tight and as long as I have a milspec bolt (not TiN coated or hard chromed), I shouldn't be needing to send my bolt in.
What about it?

 

[shooter65]

Re: AR15 barrels and headspace

That is a true statement.

 

[427Cobra]

Re: AR15 barrels and headspace

Krieger would not lie to you, but I would double check it with a no go gauge for piece of mind.

 

[-=boone=-]

Re: AR15 barrels and headspace

The main concern would be the proper torque setting with the barrel nut to achieve consistent accuracy.

 

[9H_Cracka]

Re: AR15 barrels and headspace

If you have experience and data beyond theirs then by all means question their position.

 

[HotIce]

Re: AR15 barrels and headspace

Reason I asked is because, for example, WOA wants your bolt (or offer you to buy the one they used to headspace the barrel) when shipping already headspaced barrels.

 

[9H_Cracka]

Re: AR15 barrels and headspace

Not when I get them from John (Holliger; Krieger is John also) he doesn't. Just ordered another one 20 minutes ago.

 

[HotIce]

Re: AR15 barrels and headspace

Maybe that "wants" should have been phrased as "suggests"

 

[9H_Cracka]

Re: AR15 barrels and headspace

I've talked it over at length with both John at WOP and Mike at Krieger. The consensus is that good quality non-plated USGI spec bolts vary a half a thousandths. John generally chambers between .000" and .015" of minimum and .001" to .002" for Krieger. If John does not have the bolt in hand you can expect he'll cut it at least a half thou over minimum.

I've had chambered barrels from both and narry a problem. Find something else to worry about. Just don't try to mix them in with factory chamber ammo where you are only setting the shoulder back a few thou and are well over minimum. There are many a factory barrel out there that is headspaced at around no-go or between no-go and field. That ammo will not run in a WOP, WOA, or Krieger chambered barrel. Your reloading setup needs to be able to size the case down to minimum, which actually means below minimum with a little allowance for brass springback.

 

[HotIce]

Re: AR15 barrels and headspace

Oh, I always FL size ammunition for semi-autos. And the neck sized ones are linked to a specific rifle.
You mean, you need to buy down-sized dies for their match chamber?
What barrel is WOP? Wilson (the one I currently have in my CMP rifle)?

 

[Scottmilk9]

Re: AR15 barrels and headspace

White Oak Precision. headspacing is done when installing barrel extention.

 

[HotIce]

Re: AR15 barrels and headspace

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Scottmilk9</div><div class="ubbcode-body">White Oak Precision.</div></div>
Oh, I see, thanks. Two branches of the same company. They both links to John Holliger.

 

[sobrbiker883]

Re: AR15 barrels and headspace

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: HotIce</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Scottmilk9</div><div class="ubbcode-body">White Oak Precision.</div></div>
Oh, I see, thanks. Two branches of the same company. They both links to John Holliger.
</div></div>

Yup, WOA=production parts/WOP=hand crafted

 

[9H_Cracka]

Re: AR15 barrels and headspace

WOA barrel = Wilson tube made into a SR barrel and chambered by John and staff, so not production re-sale part.

 

[skinnj1]

Re: AR15 barrels and headspace

Hot Ice-

I've barreled 10 diffenent AR barrels in the last year with a variety of bolt heads and extension manufacturers (dearth of supplies due to scare) looking back at my notes the bolts were amazingly consistant but the individual extension manufacteres varied tolerances some (all things said there was only .002" max variance on how deep I reamed the barrels).

In my opinion, (not that it's worth much) as long as a smith knows how a particular lot extensions measure with a GI bolt there should not be undue drama in not having YOUR specific bolthead.

 

[264shooter]

Re: AR15 barrels and headspace

I just put a new krieger AMU 1 in 8 on one of my rifles and it works great. I asked that same question about the bolt and got the same answer. mil spec is gtg.