New brass, new chambers?

[Rambink]

A while ago, it was being recommended that if you were having a action barreled and you wanted to use the lapau brass, That you have your chamber cut accordingly FOR lapau with maybe a .271 neck.
Since the lapau dimensions have changed, are those barrels that were being chambered a few months back no good now? How did this change impact those who were having super nice custom rifles made before the change?

Reason I'm asking is because I almost started a project about 6 months back and got sidetracked with work. I would be really bummed if I had built a $2000 rifle only to find out that the chamber I had cut was no longer top notch shortly after I had finished the rifle.

 

[Forum Boss]

Check out the thread above on the dimension report recently received from Lapua in Finland. Basically they are listing .471" as the external dimension,at case web) of their brass, but they are acknowledging that current production is .468-.469".

So, if you want minimum case growth, you can spec a reamer for .469" brass,at web). But, as someone pointed out, if Lapua goes back to .471" at some point, it may be a little tight.

Bottom line, however, we're only talking a couple thousandths difference at the web, or and extra .001" per side. That should not be such a difference as to cause problems--provided your dimensions are reasonably tight on .471" brass.