6mm BRA Info

[El Cid 92]

I'm ready to make the next jump and have decided on the 6mm BRA as it seems to be the better of many options. Brass is easier to obtain, longer barrel life, less powder, and a good magazine options.

So, can anyone help with the reamer options and best machining options - ie freebore?? Plan on using a Bartein 1:7.5" twist medium palma blank. I want to give my gunsmith all the best info that I can.

I'm thinking the projectile is the 105 Hybrid. Can I use the 6mm BR dies or is there a now a set of dies that is cut for the BRA??

Thanks in advance for the info.

Andrew

 

[steve123]

It'll require fireforming to become 6 BRA, it's improved with a 40 degree shoulder and less body taper.

So it won't be the same shape as 6mmBR, and thus need specific sizing dies. Though some are using 6mm Dasher seater dies.

Sheldon should be here soon.

 

[Lonestar1027]

Harrell's has BRA specific dies for sizing (I think they just trim a 6 Dasher) and I just use a Forster Ultra Micrometer 6BR seating die, no issues there. I use the 105 hybrids as well but I'm blanking on my exact freebore. I know it's somewhere between .105 and .125. Fireforming loads shot a quarter MOA group at 200 yards with 29.5gr of H4895. You'll love the round!

 

[Sheldon N]

So, can anyone help with the reamer options and best machining options - ie freebore?? Plan on using a Bartein 1:7.5" twist medium palma blank. I want to give my gunsmith all the best info that I can.

I'm thinking the projectile is the 105 Hybrid. Can I use the 6mm BR dies or is there a now a set of dies that is cut for the BRA??

My opinion is to go with the "Alex Wheeler" reamer specs with a no-turn neck at .272 or .273, chambered 0.004 short on a BR go gauge. Call JGS and they will know which reamer print you are talking about. Dies would be Harrells if you want a bushing die, Forster Dasher FL die shortened .090 with a neck honed to .264 if you want a FL non-bushing die. Whidden also makes a BRA die that's based off the Wheeler reamer specs. For seating a Dasher micrometer die works fine, I use a Forster.

 

[*Tavman*]

Thinking about doing a BRA myself. I just ordered the Whidden dies this weekend. I was curious about reamer specs too. Good info Sheldon, Thanks.

 

[Deleted member 121493]

So my forster 6br seater works with 6bra?