Gunsmithing Headspace delemia

[pinzmann]

I am chambering a barrel in 338 Lapua Mag. Just got close to correct headspace using a PTG gauge. I'm out about .004 so I check it, won't close. I tried a virgin Lapua brass and the bolt closed fine. I also had a extra factory Lapua round and the bolt closed on that. Tried some resized brass from another barrel [same reamer used] those pieces won't close.
So now not sure if I should continue reaming? If I do I might have trouble chambering the new brass. Don't remember having this problem with the last barrel. Any words of wisdom?

 

[2156SMK]

Re: Headspace delemia

Chamber 0.001" longer than a "Go" gauge.
Then, re-size your brass so it's 0.001" shorter than a "Go" gauge.

Don't use brass as a headspace gauge.
It will eventually come around to bite you when the brass changes...

 

[buffybuster]

Re: Headspace delemia

Virgin brass and ammo is sized to fit in the smallest chambers. Using once fired cases to determine headspace is not recommended.

The GO/NOGO gages are your guide.

 

[x ring accuracy]

Re: Headspace delemia

Trust your gauges like has been said.

 

[kiff]

Re: Headspace delemia

The Brass per SAAMI can run -.007 from chamber min . That is true with CIP tolerance also. I would say you are with in .001 . The min (go) to max (feild) SAAMI gauges have .010 between. I would leave it the way it is or only move forward .001. Thanks Dave

 

[ugsly]

Re: Headspace delemia

Dont forget to allow for crush when you torq the barrel on.

Kc