Caliber Conundrum

**squirrel_slayer** · 03-27-2017, 08:28 AM

when I was spec'ing one out I was going to go with a 1:8 twist with a .114 freebore and .271-.272 neck. this would give you enough freebore to keep most of the 105 out of the powder column and yet still give you some throat to grow (so you can chase the lands as the barrel wears) you could start with the freebore as far as .135 if you want more velocity out of the gate but your barrel life (or amount of rounds you can chase the lands with before the bullet is to far outside the case) will diminish. now if you have means to set your barrel back at will then a .125-.135 freebore may not be a bad idea. the .114 freebore would be less jump for the vmax's.

as to barrel length that's all shooter preference. most go very long barrels in the 6br to maximize velocity from the short cartridge(28-32" is quite common). I personally was starting to lean towards a 6brx or dasher(both 6br wildcats with a few gr more capacity) with a shorter barrel (22-24") to be more versatile(not it to the bench rest deal) varget is the go-to powder for that cartridge but read a few good things about 8208xbr (my go-to powder now)

again I can't remember the company off hand but there's a company who sells mag guts for aics mags that will feed the stubby case well. otherwise you may want to consider a single shot approach.

trentcwwilson · 03-27-2017, 09:03 AM

Originally Posted by squirrel_slayer

when I was spec'ing one out I was going to go with a 1:8 twist with a .114 freebore and .271-.272 neck. this would give you enough freebore to keep most of the 105 out of the powder column and yet still give you some throat to grow (so you can chase the lands as the barrel wears) you could start with the freebore as far as .135 if you want more velocity out of the gate but your barrel life (or amount of rounds you can chase the lands with before the bullet is to far outside the case) will diminish. now if you have means to set your barrel back at will then a .125-.135 freebore may not be a bad idea. the .114 freebore would be less jump for the vmax's.

as to barrel length that's all shooter preference. most go very long barrels in the 6br to maximize velocity from the short cartridge(28-32" is quite common). I personally was starting to lean towards a 6brx or dasher(both 6br wildcats with a few gr more capacity) with a shorter barrel (22-24") to be more versatile(not it to the bench rest deal) varget is the go-to powder for that cartridge but read a few good things about 8208xbr (my go-to powder now)

again I can't remember the company off hand but there's a company who sells mag guts for aics mags that will feed the stubby case well. otherwise you may want to consider a single shot approach.

I'm leaning towards the single shot more and more to gain as much accuracy as possible. And Varget is my go to powder for every caliber I have except 308. Mainly because I have almost 200 pounds of it.