Thanks for the link Peter,
I have a short Remington action lying around, and a McMillan Sako varmint style stock inlet for the Remington action. Might make a dandy little 6mm BR (for Lapua brass) varmint rifle.
So little time, so little time.
JCN

DON'T hold me to this for sure ....I have been checking for the same thing for a new barrel/chamber for a gun I have and as near as I can find out the neck length and specifications for the Norma chamber are different than the standard "6mmBR" chamber and Remington brass is different than the "Norma" brass in this same fashion.....the specs were changed after the specs were set for the necked down 7mmBR brass to make the 6mmBR brass.....check the various "chamber reamer" manufactures web sites for the drawings and specs of each chamber .......I was leaning toward the "Norma" spec chamber for a 40X rebarrel.....HTH....and again this is just what I have picked up in my looking......and haven't talked to a barrel chambering smith yet...a check at benchrest central might find more exact information......good luck and good shooting-loading!!

Peter,
Take a look at having your rifle rechambered to the 6mm XC. It is basically a slightly modified version of the 6mm-250. The velocity is a bit faster than the 6mm BR, and the cartridge is longer, which makes for easier feeding.
http://www.zediker.com/
This website has information about the 6mm XC.
Laapua makes the brass.
JCN