6mmbr?

[crv42ky]

ok, so my friend and I have been looking for some 6mm guns to use as benchrest 600 yard matches.

upon looking at various cartridges we have decided on using the 6mmbr, only problem is we don't exactly know the difference between the 6mmbr norma and 6mmbr remington.
I've read how there the same in some places and been told by some people, but then im told otherwise by others and i've read how they are different...
so, are they different? or no?

 

[tiny68]

You are probably going to get a lot more responses from the 600/1000 yd forum than this forum (which is focused on 100/200 yds BR). The link below has an excellent write up over the 6BR, its history, suggested loads, twist, and barrel lengths. More than I want to type.

http://www.6mmbr.com/6mmbr.html

Luck on your build, tiny

 

[Mike Bryant]

The main difference between the old 6 BR Remington and the 6 BR Norma is that when Lapua made the cases for the 6 BR Norma they made the brass app. .004" larger in diameter at the web than what the Remington brass measured. As a result, a reamer that was made to minimum benchrest specs would measure right at .002" larger in diameter at the web than what the Remington brass measured at that point. This would make the chamber .002" smaller in diameter at that point than what Lapua brass measured. As a result, most gunsmiths chambering for the 6 BR have reamers made for Remington brass that they haven't used in years and reamers for Lapua brass that they use whenever they chamber a 6 BR barrel. FWIW, a chamber made for Lapua brass will accept Remington brass, but not vice versa. They also lengthened the neck length about 025" over what the Remington brass was. That's the basic difference between the old 6 BR Remington and the newer 6 BR Lapua.