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Old February 16, 2009, 05:25 AM   #4
longrifles, Inc
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Join Date: February 16, 2009
Location: Sturgis, South Dakota
Posts: 152
Lapua brass

First, regarding head space gauges and not fitting as tight at you'd like.

There's a reason for this. No single tool maker who caters to the gun industry has control over what other tool makers do or the tolerances they run.

To better put this in perspective, there's at least a dozen different 308 Winchester variants that all headspace off the same gauge, yet all have different dimensions.

Say your Clymer gauge was a 308 built for a SAAMI plain jane chamber and i built to a more resemble a piece of brass. Your attempting to check a minimum SAAMI chamber 308 variant and when you attempt to close the bolt the gauge seizes in the chamber ruining the gauge and requiring you to get out the cleaning rod to pound it back out. Once you remove it you see a nice ring/gall mark in your chamber.

Not cool.

This is why the gauge is purposely made undersize from the nominal chamber diameters. Otherwise you'd need a gauge specific to every reamer out there. That's not realistic and it'll lead to gunsmiths head spacing chambers with the wrong gauge. It's awfully easy to screw up now as it is and requires a guy to be very diligent and careful when setting up a chamber.


Now, for your problem.

Lapua brass, awesome stuff. I use it exclusively in my rifles. A while back I started noticing little shiny rings on my bolts and stuff. When I made the switch from Norma to Lapua brass on my 338LM I had to modify the bolt and extractor some to get it to work right. (Nesika action)

So what gives I wondered. I learned that Lapua brass runs toward the big end of the tolerance spectrum in a lot of their cartridges. If you have a chamber or a bolt face that is on the conservative side of the tolerance limit then its very possible to have issues.

I had to open my bolt face an additional .010" and whittle on the extractor in order to get mine to work right. I never had to do with with Norma brass.

My 6mmBR 300 meter free rifle also uses Lapua brass and every once in awhile I get a case that is a little fussy. It's not often but it does happen.
As with anything else, when you get to one extreme or another, the whole package has to be taken to the next level if you expect everything to work right.

Good luck

Chad
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