Update: 6br .268 neck

[joshb]

A while ago I bought a used 6br barreled action. The barrel was marked .268. The marking was done with one of those etching pens, by the look of it. I had been told it was a no turn neck, by previous owner. Well, i dealt with it by buying a PMA neck turning set, and learned how to turn necks. I turned a whole blue box of Lapua down to a loaded dimension of .266. Put a bunch of test loads together and shot them. Lots of fun along with a little educational advancement. Today, I started to set up some more loads. As I was measuring my 1x fired cases, I noticed something strange. My necks were all .270 to .271.??? My Cerrosafe had finally come in, so I figured I should put it to work.(My first try at that, too) The casting, at the recommended 1hr mark revealed that My chamber has a .272 neck. Well, the gun shoots great, so far, and I've learned a lot. Also relearned a couple things about "assuming". There are a few lessons here, so I thought I'd post it. The "more experienced guys" might get a chuckle and the newer guys might get something out of it. Also: i got a .264 bushing for my Whidden die. With a .272 chamber, i'm guessing my brass might not last as long? I'll be getting another box of Lapua and some new bushings. I should skim the next batch to ? "What dimension"? , or not touch the necks at all? Thanks, Josh.

 

[ShootDots]

I would not worry about it. You are expanding and contracting (firing / sizing) the necks beyond "normal", however, it works. The only downside is, IF you consider it a downside, is you will probably need to anneal every firing. Some people do that anyhow with brass that is not expanding at your rate. So worry not, go have fun..

 

[Tim Singleton]

Seat the bullet you are shooting in the new brass and measure with your micrometer. Shoot for IMO a minimum of .002" total clearance and .003" won't hurt a thing.
You may not need to turn at all. At most a skim as you said

 

[ShootDots]

As Tim stated, you don't need to turn your necks at all. However, skim turning to clean up the necks to the tune of about 80 pct. will still help, in my opinion, to aid in accuracy.. But bottom line>>> you are fine!