I would size them and then see what happens on second firing. My thought is your feeling a little more than usual resistance due to the cases being crush fit but to me the primers and the charge weight/speeds seem perfectly normal. Also make sure chamber is clean oil or cleaners can cause issues.
6mm BRA
- Thread starter cjherrman
- Start date
I've never used Petersen brass, but it looks like others have the same issues in mild loads upon first firing with that brass brand.
So as far as accuracy goes should I put some more rounds down the tube before I worry or call the smith? I picked bra because everyone always talks about how easy it is to load for especially fire forming.
I would load up 20-30 round all exactly the same (30gr varget and a Berger 105) and shoot a bunch of 5 round groups to really see what it's doing. One group of this and one of that isn't telling you anything.
What are your expectations for the barrel?
Are you able to personally shoot up to those expectations consistently?
My expectation was 1/2” 5 shot groups or better consistently at around 2800-2850. Obviously the smaller the group and faster speed preferred but I was trying to set a very realistic goal. Yes I’m capable of the 1/2” groups, I was just nervous about the pressure signs, and the Hornady bullets grouping a solid 1.5”, along with a few of the Berger groups. After hearing it’s probably fake pressure signs from the brass I’ll load up a bunch like you said, and if there’s still no hope for accuracy after that I’ll go from there.
Thanks!
03machstock
be sure to jam your fire forming rounds to help form the shoulder and avoid spring back good luck and good shooting.
You do not need to jam to fire form BRA....the AI chamber is cut -.004 or should be so you get a slight crush fit when cambering standard BR brass.
Went out to the hills yesterday. I wasn't expecting a great day because:
- I'm trying out N540 in my 6 BRA and I haven't done any seating depth tuning with it.
- I've been having issues with my 300 PRC.
The N540 performed very well in my BRA
We had the following targets set:
- 10" @ 420 for tripod practice
- Hostage target (2 flappers) at 950
- 24" gong @ 1630
- 33" square @ 1820
Wind was ~4-6 mph variable
I had loaded the entire batch of ammo with 30.6 grains of N540 pushing Berger 105s and got a 2879 average with a 6.4 SD. Both are likely a bit higher than I should normally get as I was running the rifle a little warm.
Results at targets:
- Hitting the 10" target off the tripod at 420 yards was a somewhat trivial exercise.
- I only spent a handful of rounds at the hostage/flapper target. Shot prone and hit the shoulder flapper a couple times and the center flapper a couple times.
- At 1630, I hit 4 out of 10 while prone and 2 out of 10 from the tripod. This is the farthest I've shot off the tripod.
- At 1820, I hit 4 out of 12 while prone. I did not attempt this target off the tripod. This is the farthest I've taken the 6 BRA - previous longest was the 24" at 1700 at the same shooting location.
- At 1630, the target didn't move on a hit, and we needed to rely on the splash hitting the ground underneath, as well as the sound of the gong, to determine a hit.
- At 1820, we could only discern a hit if it was low on the target or if we heard the gong. If the wind was blowing, we would likely not have been able to determine many hits.
This is the 1630 yard 24" target. We shot it with 338 (Berger 300s), 300 PRC (Berger 220s) and the BRA. Care to guess what marks are from the BRA?
Long story short, N540 performed pretty well. I'll be doing more testing to find a good charge (possibly for a little more velocity) and to play with seating depth, but I'm pretty happy with it.
- I'm trying out N540 in my 6 BRA and I haven't done any seating depth tuning with it.
- I've been having issues with my 300 PRC.
The N540 performed very well in my BRA
We had the following targets set:
- 10" @ 420 for tripod practice
- Hostage target (2 flappers) at 950
- 24" gong @ 1630
- 33" square @ 1820
Wind was ~4-6 mph variable
I had loaded the entire batch of ammo with 30.6 grains of N540 pushing Berger 105s and got a 2879 average with a 6.4 SD. Both are likely a bit higher than I should normally get as I was running the rifle a little warm.
Results at targets:
- Hitting the 10" target off the tripod at 420 yards was a somewhat trivial exercise.
- I only spent a handful of rounds at the hostage/flapper target. Shot prone and hit the shoulder flapper a couple times and the center flapper a couple times.
- At 1630, I hit 4 out of 10 while prone and 2 out of 10 from the tripod. This is the farthest I've shot off the tripod.
- At 1820, I hit 4 out of 12 while prone. I did not attempt this target off the tripod. This is the farthest I've taken the 6 BRA - previous longest was the 24" at 1700 at the same shooting location.
- At 1630, the target didn't move on a hit, and we needed to rely on the splash hitting the ground underneath, as well as the sound of the gong, to determine a hit.
- At 1820, we could only discern a hit if it was low on the target or if we heard the gong. If the wind was blowing, we would likely not have been able to determine many hits.
This is the 1630 yard 24" target. We shot it with 338 (Berger 300s), 300 PRC (Berger 220s) and the BRA. Care to guess what marks are from the BRA?
Long story short, N540 performed pretty well. I'll be doing more testing to find a good charge (possibly for a little more velocity) and to play with seating depth, but I'm pretty happy with it.
Interested in hearing more about your rifle and the results from it. I'm considering a PVA barrel in 6 bra and using varget with Peterson brass. Thanks in advance!
Anyone have issues with Alpha BRA brass in their PVA prefit? As long as I’ve been shooting my batch of Alpha brass I’ve had problems with intermittent stiff bolt close. I played with shoulder bump but that didn’t solve it. The last match I shot, heard a few guys had the same issue with 6BRA and alpha specifically with PVA prefits but this was news to me. They all suggested Lapua 6BR brass
I shot it very little before I put my 223 barrel back on because I had a bunch of shooting to do and my fireform loads were just so so. I just recently screwed my 6bra barrel back on and shot a few loads through it that showed promise (still just fire form basically just trying different bullets). I’m going to confirm that load soon and if all is well just shoot that until I get all my brass fire formed, then start actual load development.
I've mentioned this multiple times on this site. If you can get Lapua brass for your caliber, you get Lapua brass. I've gone so far as to limit future cartridge considerations to only those that have Lapua available. EDIT: I would do RWS too, but they make brass mostly catering to European calibers.
For 6 BRA, it means forming 6 BR. Not a big deal at all - it's one of the easiest calibers to form.
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You should look at the alpha 6bra findings on accurate shooter. It was tested a ton with the long range bench rest crowd. They had phenomenal results and then all of a sudden issues occurred. As far as I know it’s the only caliber that’s caused any issues. Clickers and stiff bolt closes which one would have to assume it’s from the base not the shoulder.
I run alpha 6br brass for my 22bra and and Lapua 6br brass for my 6bra and 6br and have 0 issues with any of those but purposely avoided the alpha 6bra brass due to issues. I don’t know if they were ever fixed but for the money I didn’t want to chance it.
I tried to skim read through all posts but I dont think I've seen anything on 6BRA and berger 109's. I apologize in advance if I missed it.
Anyone shooting 109's out of a BRA? I have one with .104" FB and 28" barrel. Thanks in advance
Anyone shooting 109's out of a BRA? I have one with .104" FB and 28" barrel. Thanks in advance
Yeah it seems to be the case that Lapua brass is the way to go UNLESS you get a reamer specifically for Alpha Brass. It would seem that pre-fit barrels for 6BRA seem to universally shoot Lapua brass smoothly, but Alpha has hit or miss depending on the reamer used.
I've got a 6mm BRA chambered barrel in progress at BugHoles and want to order some brass. I would prefer Peterson brass unless I have to neck turn or something like that. Will Peterson brass be ok or should I buy Lapua brass?
I live a few miles from their facility and have heard a lot of good results from other shooters using their brass. Also trying to support a USA based company.
I'm on my 6th or 7th firing of Peterson's 6BRA brass. You could probably split hairs and find a reason why Lapua is better? Not sure.
From my experience, the Peterson is no slouch.
Has anyone tried dtacs in the bra? I shot out my first barrel with 105s at 2783 fps, and I'm fine with slower speeds in 2025. Seems like most people talking dtacs were hot rods looking for 2950+ speeds and "couldn't get up to speed" before hitting pressure. I'm just fine with 2750-2825, especially if the accuracy is there. I've got 1500 dtacs gathering dust on the shelf. I've got a new bra barrel inbound in the next few weeks and wondering if I could make the heavies work as well as the 105 hybrids.
I tried 112 Matchburners in the BRA (I've also used DTACs in CM, and I think the 112s are easier to work with).
I couldn't get much faster than 2700 with a 24" tube and dropped the idea.
Finally got a chance to try fire forming Lapua 6BR brass. I regret not doing this sooner. Accuracy and numbers were stupid good. Bolt cycling was the smoothest it’s ever been. All the bolt clicking and stiffness went away.
Loaded 29.8gr Varget and 107s with 0.020” of jump on the 550. Seems like the absolute easy button
Loaded 29.8gr Varget and 107s with 0.020” of jump on the 550. Seems like the absolute easy button
