anyone else shooting a 6br with the standard 6br remington chamber?

[cornhusker]

my barrel has the standard rem chamber so the bullets can not be set out
as far as other chambers.In fact I use the laoding data from the Berger
manual..All the loads for 6br Norma will not work..
So I was wondering if you have the same,what might be your most
accurate loading..My barrel is 1 in 8 twist and the accuracy is not very
consistend..I may be the operator..lol So please feel free to share
your comments with this old bastard..Thanks

 

[ksthomas]

Cornhusker,

You have a standard 6mm Rem BR chamber and throat, but a 1x8" twist, is that correct?

 

[cornhusker]

Cornhusker,

You have a standard 6mm Rem BR chamber and throat, but a 1x8" twist, is that correct?

correct,,,,

 

[ksthomas]

Cornhusker,

What you've got there is essentially a football bat; neither fish nor fowl. The 6mm Rem BR is set up with a short throat and usually something along the lines of a 1x14" twist barrel. They were designed and intended to be used with the 68-70 grain FB bullets used for short range BenchRest shooting. The 6mm Norma BR used the same case (and yes, there has been a minor length change early on with this case, but it doesn't figure into this) but with a faster 1x8" twist and a considerably longer throat to accommodate the 105 grain VLD style bullets. Since Norma is a CIP member, they had to rename the "new" round (CIP regulations require this anytime a dimension of either cartridge, chamber or both are changed), hence the 6mm Norma designation for what most Americans would otherwise consider the exact same round. Yours was apparently built using a reamer throated for the conventional 6mm Rem BR specs, but with a twist intended for the longer, heavier bullets. As a result, it's not ideally suited to either. Too fast a twist (though you can still shoot them) for the lighter bullets that fit the throat, and twisted for the heavier bullets that seat too deeply.

I'd suggest taking this one to a gunsmith and having it throated for the longer bullets, if that's what you want to shoot. Hope that helps!

 

[cornhusker]

Cornhusker,

What you've got there is essentially a football bat; neither fish nor fowl. The 6mm Rem BR is set up with a short throat and usually something along the lines of a 1x14" twist barrel. They were designed and intended to be used with the 68-70 grain FB bullets used for short range BenchRest shooting. The 6mm Norma BR used the same case (and yes, there has been a minor length change early on with this case, but it doesn't figure into this) but with a faster 1x8" twist and a considerably longer throat to accommodate the 105 grain VLD style bullets. Since Norma is a CIP member, they had to rename the "new" round (CIP regulations require this anytime a dimension of either cartridge, chamber or both are changed), hence the 6mm Norma designation for what most Americans would otherwise consider the exact same round. Yours was apparently built using a reamer throated for the conventional 6mm Rem BR specs, but with a twist intended for the longer, heavier bullets. As a result, it's not ideally suited to either. Too fast a twist (though you can still shoot them) for the lighter bullets that fit the throat, and twisted for the heavier bullets that seat too deeply.

I'd suggest taking this one to a gunsmith and having it throated for the longer bullets, if that's what you want to shoot. Hope that helps!

I appreciate your reply..I tought that as well,but am not a certified gun crank..I will leave it as is for now and try the shorter flat base bullets..it does like the lighter bullets over the heavy ones..I appreciate your replies..thanks John

 

[ksthomas]

Cornhusker,

Over-spinning a light weight bullet with a "too fast" twist isn't the problem that most people think it is. It will magnify and accentuate any center of gravity or concentricity problems in the bullets, and that WILL increase group size. However, if you're dealing with good quality bullets, there's essentially nothing to magnify. Use decent quality bullets and even the light weight projectiles should shoot quite nicely for you.

Lengthen the throat to accommodate the longer 105-107 designs if you really want to step out the range, but it's certainly not necessary to do so if you're satisfied with the shorter bullets you can chamber with the shorter throat. Should be a good shooter, and it's a great little cartridge.