6mmBR To Bump or not to Bump

[Remington243]

Someone said to me a long time ago,, I think,, that full length sizing 6BR wasn't necessary because it didn't have the powder load to expand the brass like other higher capacity loaded ammo. I am considering to bump or not to bump the shoulder. Two questions I guess.
Yes, this is my first time reloading the 6mmBR.
Thank you.

 

[Lance21]

My experience with the 6 br is bump it 2 thou and load it.

 

[Bill Norris]

Yes, bump .002 with the 6BR

 

[Webster]

Someone said to me a long time ago,, I think,, that full length sizing 6BR wasn't necessary because it didn't have the powder load to expand the brass like other higher capacity loaded ammo. I am considering to bump or not to bump the shoulder. Two questions I guess.
Yes, this is my first time reloading the 6mmBR.
Thank you.

The pressure reached is still over 55,000 PSI. Not just the powder charge but the combination of case volume and powder. They are shooting 6PPC in competition at over 60,000 PSI. If you can easily chamber a fired round there is no reason to bump. When it gets a little harder to close the bolt that is your reference to bump from.

 

[jackieschmidt]

With all due respect to your friend, he is wrong.

capacity does not “blow out“ cases, pressure does. The 6BR can be considered a high pressure round, since I feel safe in saying that the majority of Shooters using it in various competitions are shooting in the neighborhood of 55,000+ psi.

If you are planning on hand loading yhe cases numerous times, you might as well start out full length sizing from minute one with around 2 to 3 thousandths shoulder bump because after a few firings you will have to anyway.

 

[M-61]

For me the only reason to bump’ is to correct a problem. Arbitrary bumping the shoulder back to some demension you have determined works the brass needlessly. Stiff opening of a bolt would be reason to bump, but if everything is working fine I say no. I take the trouble to set the headspace as small as I can. Maybe one thousandths if I can do it. I’m not adding a couple of thousandths or more to see if I can really get that brass to stretch. I’m not looking to see how many reloads I can get out of a cartridge but I’m not going to shorten it by constantly squashing the case and then watch it stretch when fired.
I’m in no way telling you what to do. I’m merely saying what I do in my br rifles. And there’s plenty of folks that are happy bumping. Nor am I saying my way is better. I’m saying what works for me.

 

[divingin]

Someone said to me a long time ago,, I think,, that full length sizing 6BR wasn't necessary because it didn't have the powder load to expand the brass like other higher capacity loaded ammo. I am considering to bump or not to bump the shoulder. Two questions I guess.
Yes, this is my first time reloading the 6mmBR.
Thank you.

Eventually you'll have to. I normally neck size, but have to FL size to reduce base-to-shoulder every half-dozen firings or so, whether I'm running moderate or higher loads.

And 6BR has close to the same max pressure as 308 (or at least within a few thousand PSI, depending on who you talk to - the actual BR Norma spec is in CUP, which has no direct correlation to psi, so "max" can be considered anywhere from 52K to 58K psi.) I don't buy the "won't expand the brass" thing.

 

[Mark W]

I bump everything .002 because I want the bolt to close as easy as possible.

 

[Bill Norris]

I bump everything .002 because I want the bolt to close as easy as possible.

Yea, I find it better to F/L size every time rather than letting the brass move a small amount until it finally needs to be bumped. Eric Cortina says it affects accuracy but who knows ?

 

[jpx2rk]

Try it both ways and see if accuracy is better one way or the other.

 

[Old Navy]

I guess you can do what ever works for you on a target rifle. If you are going hunting with that shooter you better bump at least .003. I wore out several 6Br and BRX barrels with a 100 Lapua cases bumping .002-.003".