First adventure with a BR family cartridge - impressed so far

[stevieb92]

This is my first adventure with a BR family cartridge and so far I'm super impressed. I had a spare Bartlein heavy varmint barrel chambered in 6 CM (by SPR) for my main PRS rifle laying around so I decided to send it back to SPR to re-chamber it for 6mm BRA. I only lost 1.40 inches of barrel length, so it is now 24.6 inches instead of my normal 26 inch preference. This is also my first use of Peterson brass and Berger bullets. I can say I'm very happy thus far with only 70 rounds down the barrel and with zero load development.

The targets below were shot two different days. The targets to the left of the black sharpie mark were 3/28 which also included scope adjustments. The targets to the right of the black sharpie mark were 3/31 and no scope adjustments. The farthest right group had a weird issue. The CCI 450 primer wouldn't ignite. I had to cycle the bolt over a dozen times before it finally ignited, which ended up making that group just over 1 moa. I guess I was ticked off and not set. Had a real nice group going on that one until the primer issue. In all my years of using CCI primers, this is the first time one didn't work. WTF?

 

[OREGUN]

4895 and a 105 Hybrid is an award winning combo. Keep working with it. That upper left 3/31 group is close to what you should expect. One ragged hole or smaller. Regarding the primer, I have had a few not go off over the years. Usually I could trace it to something I did (set a can of fizzing soda next to a primed tray of cases, for example). If it’s a one off, don’t stress it.

 

[stevieb92]

4895 and a 105 Hybrid is an award winning combo. Keep working with it. That upper left 3/31 group is close to what you should expect. One ragged hole or smaller. Regarding the primer, I have had a few not go off over the years. Usually I could trace it to something I did (set a can of fizzing soda next to a primed tray of cases, for example). If it’s a one off, don’t stress it.

That's what I've read about the powder and bullet combo, so I thought I would give it a whirl. I'm not going to get too concerned about it until I get closer to 200 rounds down the barrel and do some load development. For those 9 groups, it averaged .64 moa, so considering that I'm happy. If I can get it to shoot consistently under .5 moa with some development, that will be just fine for my needs in PRS. The first firing pin hit on the primer looked normal, but it didn't ignite. It was definitely a surprise.

 

[kthomas]

6BRA is an absolutely fun and fantastic cartridge, enjoy!

 

[TylerN]

Once you go to a BR variant it's hard to find a reason to go back to 6 CM.

Regarding the primer FTF, I'd assume the BR case in a BRA chamber crushed forward into the chamber and that's what caused the FTF. Even though the BRA shoulder neck junction is set back .004" compared to a BR I believe the minimal amount of contact area means the brass might get jammed too far in the chamber and cause light strikes. So I'd assume that's just a fire forming quirk and once your brass is formed out you won't see that anymore.

 

[OREGUN]

BR brass is a .004” CRUSH fit in a BRA chamber (that is cut correctly, which bugholes is certainly doing). The case would be pressed firmly back against the bolt face.

 

[stevieb92]

BR brass is a .004” CRUSH fit in a BRA chamber (that is cut correctly, which bugholes is certainly doing). The case would be pressed firmly back against the bolt face.

Yeah, I could feel that light crush on each round.

 

[TheNarrator]

Sweet setup...