Lapua Brass

[Xtrema]

A little while ago a bought a box of Lapua brass in 260 Remington.

I loaded the brass with CCI large rifle primers which slid in easy using my Sinclair hand priming tool.

After firing and good thorough primer pocket clean and usual case prep i found it impossible to hand prime as the primer pockets have clearly tightened up considerably. Even using the priming tool on my Forster press was a tough job and resulted in some damaged primers.

I was necessitated to use a primer pocket reamer to get the primers to slide in nicely. The reamer removed a surprising quantity of brass too which surprised me.

I'm wondering if anyone else has experienced this with Lapua brass?

[jcampbellsmith]

You don't say, but I take it this was new Lapua brass or second-hand? I have used Lapua, Nosler and Remington brass with CCI 200 primers and have to date encountered no issues.

 

You're sure you've not got your decapping rod set too low and the expander ball isn't hitting the inside of the case head and distorting the case head? I would be taking the resizing die to bits and cleaning it and re-reading the die setup instructions.

 

Regards

 

JCS

[DW58]

There's definitely something odd happening here - primer pockets can loosen in time, but I've never heard of them getting tighter.

 

Paging Laurie and Vince ... ... ...

[Xtrema]

You don't say, but I take it this was new Lapua brass or second-hand? I have used Lapua, Nosler and Remington brass with CCI 200 primers and have to date encountered no issues.

 

You're sure you've not got your decapping rod set too low and the expander ball isn't hitting the inside of the case head and distorting the case head? I would be taking the resizing die to bits and cleaning it and re-reading the die setup instructions.

 

Regards

 

JCS

Yes this was new brass.

I don't decap with the resizing die, just a Lee decapper and then straight into the ultrasonic bath.

I do full length resize. I have a Forster full length resizing die with the expander ball just below the vent hole as per instructions. My rifle has a very tight chamber as even full length resizing requires little effort. I get your point about the possibility of hitting inside the case head but i'm sure i would feel it if that were the case. Anyway, i full length resized before priming for the first time and the primers slid in nicely then.

I have heard that Lapua produced a batch of 260 Remington brass which had slightly convexed case heads which flattened out upon firing thus tightening the pockets.I'm not sure how true it was but it would explain why reaming the pockets only removed metal down to just over half depth.

I have been reloading for over 30 years and never come across this before.

Rather disappointing as Lapua brass is normally the best, and of course the most expensive.

[The Gun Pimp]

If someone finds a way to make primer-pockets tighter it would be a winner! With annealing - all we need now is a way of tightening primer-pockets.

 

But, when I read "my rifle has a very tight chamber" I always think "Really?"

 

Who the f*** goes to the trouble of ordering an under-size reamer - why would ya?

[Xtrema]

I got this from the Accurate Shooters forum.

It was posted a few years ago and concerns Lapua brass of another calibre.

 

"Another issue, that has been reported with the .220 Russian Lapua brass (that I have not experienced, but which may be a batch to batch variation) is pocket tightening caused by new brass having slightly convex heads. In this case, firing flattened the head, while simultaneously tightening the pockets."

 

So it's not unheard of then?