Home Forums Hunting & Shooting Gunsmithing Headspace question

Sent rifle out to have barrel cerakoted, the barrel was removed from action, coated and reinstalled however the barrel was not indexed exactly as before. The barrel would have needed approx 3/16” more tightening for the caliber designation to be where it was prior to coating. Gunsmith said it was an oversight on his part but would not affect headspace. He offered to fix it but that would require shipping both ways. Is this correct that it will not affect headspace?

Your headspace will now be longer than it was before.

what Al said, but adjust your die for it

So your new headspace could be 3-4 thousandths difference from original; I think the first thing I would do would be to check everything with headspace gage(s). I can understand your gunsmith's reluctance because tightening further could damage the Cerakote, but you didn't state whether he rechecked the headspace, etc.

It's likely there's coating on the barrels abuttment surface.

When torquing a 1-1/16×16 or 18 thread barrel to 100 lbs/ft, the final 1/16" of rotation after hand tight normally doesn’t change the headspace.

Good shootin' -Al

Yeah, I was editing my original response cause I had my head up my rectum

I think your 3-4 number is pretty realistic. -Al

While it may well be due to a build up on the contact surface of the shoulder, it is at least as likely that the buildup is on the threads. In this scenario, the contact at the shoulder is the same, but the barrel tightens up sooner. The headspace doesn't change but the index does. We take advantage of this when we set up threads on a barrel which is going past register. With the threads displaced toward the shoulder, the barrel tightens up sooner, but HS is unchanged. GD

Very possible. I can't imagine anyone coating tenon threads but....

Think ceramic anti seize Al...😲

Don't get 'em pondering thread stretch with traditional 60 degree 'V' threads.

Too much, too soon ...

I just finished setting back and rechambering a BRNO ZKK on which the threads were most definitely coated. This rifle did have excessive headspace, but not because of the coating. Of course, the BRNO doesn't depend upon the shoulder/thread relationship. It seats the barrel on the inner ring. I only mention the coating on the threads thing to show that it can have an effect in either location. GD

Good point.

Hopefully, the OP will give an update. -Al

I'd just adjust for it and move on.
Been using the same brass in a 308 660 since the late 80s,
that gun will close on a no-go, and it takes a .010 chip to keep the bolt from closing.
Same brass has been loaded 4 or five times at least, not a one failed.
At least not since that one separated 30 odd years ago and prompted the headspace check.

My loads will not fit in another 308, if I ever get the Hyem project gun done I'll
probably just get it it's own dies.

I would be more concerned with the coating on the action face, and/or barrel shoulder, preventing a solid lock up in the barreled action than I would headspace issues. Having a stable joint is a necessity.