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6 BRA headspace issue

Hi all, having an issue with my 6 BRA, I've got some used 6 BRA brass from two other rifles and it's ~0.012" shorter at the shoulder than cases fired in my barrel.

Background is that I bought the barrel for my Tikka secondhand, I know it's a no turn and I assumed it was otherwise the standard Wheeler #1. It came with 100 pieces fired brass and I checked the headspace against them after I installed the barrel, bolt was tight but would close on a fired case. It wouldn't close on a fired case with a single layer of Scotch tape, and the shoulder measured the same on cases fireformed on my action as the fired cases I was sent, so I'm sure it's not a barrel installation issue.

I got 20 6 BRA cases from one guy and they were 0.007" short at the shoulder (using a SAC comparator), I didn't use them but figured hey maybe that guy had a short chamber or sized them way too far. It's only 20 cases and they were free, I wasn't worried about it. But recently I just bought 250 pieces of brass from a different guy and they measure 0.012" shorter than my fired cases. So now I think it's most likely that my chamber is longer than standard. I now have 300 pieces fireformed to my chamber and 260 fireformed in other chambers that seem very nice but have way too much headspace, so I'm trying to figure out my next move.

As I see it I have four options:
1. Make a false shoulder and fireform (expand the 'short' brass to 6.5, then size down to my chamber's shoulder)
2. Load bullets long and jam to fireform
3. Sell the 'short' (really standard 6 BRA) brass
4. Shave back my barrel to standard spec and bump all my long brass back down to standard?
Any suggestions among these or other ideas?

I'm leaning toward #1 but don't want to work the brass (and myself) that much if it's not needed. I do have an annealer so I'm not worried about that part. Yes I probably should have just fireformed everything and not run into this problem but I'm cheap and used brass is cheaper than new. Thanks in advance.
 
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Since standard 6BRA chambers should crush very slightly on brand new 6BR brass for fireforming, I'd have the barrel reworked to fix it.

If the headspace is off by 1/64" of an inch, then it begs the question of what else was done well.

I believe it's possible to use standard 6BR chamber gages - not sure why this barrel would be so far off.
 
My guess is, according to the given measurements, that it will close on a 6BR go gauge.
OP states the barrel was purchased used. I think there is an issue with tolerance from the original action to his. Thing is, it may have been off on the original action as well.
 
My guess is, according to the given measurements, that it will close on a 6BR go gauge.
OP states the barrel was purchased used. I think there is an issue with tolerance from the original action to his. Thing is, it may have been off on the original action as well.
Thanks, I'll get a 6 BR go gauge. I don't think it's a difference between actions as like I said, the fired brass from the other action measure the same as fireformed brass on my action.
 
Had a bit of the same problem. A good friend of mine also on this forum, told me anneal twice and if needed use a 45 ACP sizer die. Worked for me. My brass is back to chambering easily.
 
Had a bit of the same problem. A good friend of mine also on this forum, told me anneal twice and if needed use a 45 ACP sizer die. Worked for me. My brass is back to chambering easily.
Okay, so I understand correctly, you got some brass with the barrel that had been formed to that barrel on another action. You also got brass from two other sources. Now you're trying to sort it all out and make it work. You got twenty pieces from someone at it was .015 shorter. I don't quite understand so verify the measurement on other 250 that apparently came form yet another chamber. Are they .015 shorter like the twenty as well?
 
Okay, so I understand correctly, you got some brass with the barrel that had been formed to that barrel on another action. You also got brass from two other sources. Now you're trying to sort it all out and make it work. You got twenty pieces from someone at it was .015 shorter. I don't quite understand so verify the measurement on other 250 that apparently came form yet another chamber. Are they .015 shorter like the twenty as well?
I assume this is directed at me rather than jackson. Yes you have it right, the 20 are 0.015" short but also the 250 are 0.015" short. Leading me to believe it's actually my chamber that's long.
 
Oh sorry, yes it was for you.
Do you have a Hornady or Whidden comparator? I could do some measurements to compare too then.
 
Oh sorry, yes it was for you.
Do you have a Hornady or Whidden comparator? I could do some measurements to compare too then.
Thanks, that would be a good sanity check. Using the Hornady B350 comparator:
Virgin Lapua 6BR: 1.155"
Fired 6BRA in my chamber, unsized: 1.178"
Other rifle #1 (20 pc brass), sized: 1.172"
Other rifle #2 (250 pc brass), sized: 1.166"

I checked again with the SAC comparator and it matches that rifle #1 brass is 0.006 - 0.007" longer at the shoulder than rifle #2 brass, so I had it wrong that they were the same.
 
Virgin Lapua 6BR: 1.156
Fired Lapua 6BRA (4 firings): 1.175
Loaded Lapua 6BRA: 1.173
Virgin Alpha 6BRA: 1.170
So, you can see the Alpha is going to have to blow out .005 and my plan is to use the powder charge of about 29.5-30 grains H4895 for the first firing and bullets that shoot well jammed.
I would advise against doing a flash shoulder on the shorter brass, even with a good anneal before doing it.
In your predicament I would just jam them and fire with a lower than normal powder charge. After that I would verify that there are no incipient was head separations showing up.
 
Virgin Lapua 6BR: 1.156
Fired Lapua 6BRA (4 firings): 1.175
Loaded Lapua 6BRA: 1.173
Virgin Alpha 6BRA: 1.170
So, you can see the Alpha is going to have to blow out .005 and my plan is to use the powder charge of about 29.5-30 grains H4895 for the first firing and bullets that shoot well jammed.
I would advise against doing a flash shoulder on the shorter brass, even with a good anneal before doing it.
In your predicament I would just jam them and fire with a lower than normal powder charge. After that I would verify that there are no incipient was head separations showing up.
Thank you so much, the fact that I'm not so far off your numbers is a relief. I'll plan to jam and shoot some lighter loads.
 
Welp, just found this post Alex recommending a guy get a barrel reworked over 0.011" of excessive headspace rather than try to jam and fireform.
 
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Thanks, that would be a good sanity check. Using the Hornady B350 comparator:
Virgin Lapua 6BR: 1.155"
Fired 6BRA in my chamber, unsized: 1.178"
Other rifle #1 (20 pc brass), sized: 1.172"
Other rifle #2 (250 pc brass), sized: 1.166"

All the 6BRA barrels that I've had (two different smiths, two different actions) have all measured right at 1.173 to 1.174 on fired brass with my Hornady .350 comparator. I also purchased once fired brass second hand and it matched my chamber within a thou or so.

While it's equally possible that there's variation between our comparators, your numbers suggest that your Tikka barrel is a bit long and the 250 pieces of brass were from a short chamber.

The correct chambering for a 6BRA is 0.004 short of a 6BR go gauge, so if you get a go gauge I would make sure the rifle is correct first before moving on to fireforming any of the brass.
 
All the 6BRA barrels that I've had (two different smiths, two different actions) have all measured right at 1.173 to 1.174 on fired brass with my Hornady .350 comparator. I also purchased once fired brass second hand and it matched my chamber within a thou or so.

While it's equally possible that there's variation between our comparators, your numbers suggest that your Tikka barrel is a bit long and the 250 pieces of brass were from a short chamber.

The correct chambering for a 6BRA is 0.004 short of a 6BR go gauge, so if you get a go gauge I would make sure the rifle is correct first before moving on to fireforming any of the brass.
Thanks, another data point is also useful. I'm wary of comparator variation too, that's why I posted the virgin 6 BR measurement as well. I agree, it seems both my chamber is slightly long and the chamber for the 250 pc was short.

Hey Eric - that guy was me.. What is your plan? I'm happy to measure and help if you need more info to diagnose.
Hi dnellans, are you the guy I bought the 250 pc from? You've got a very different username over on SH. I appreciate the offer, the measurements on the brass seem to agree with the above, both our barrels are slightly off in different directions. If you'd take a return I would appreciate it but I don't expect it. If not, I may contact DJ's about hydroforming or still curious what people think about jamming and fireforming that brass.

I couldn't find a 6 BR go gauge in stock, so I ordered a 6 BRA go gauge from PTG, but that's likely to take a while (it said 6-8 weeks). Assuming that confirms my chamber is too long, I'll try to find a smith locally to face down the barrel. All my fireforming has went well, with no pressure signs at 2763 fps using 29.6 gr Varget and 105's. It feels like a crush fit compared to sized BRA cases but maybe I'm fooling myself.
 
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Nope - not the guy who sold you brass. I'm the guy in the other post you found who had a BRA issue.
Turns out my "custom" BRA gauge I had made was not correct. I can measure it against other data points and it is simply too long. To make matters worse, I sent it back to the manufacturer to "check" and they claimed it was fine and returned it to me with a very obvious chip out of the back face of it.

I hope you have better luck with PTG than I did (with another vendor), but I'd also do some measuring on it when it comes to see if it all makes sense.
 
Thanks, another data point is also useful. I'm wary of comparator variation too, that's why I posted the virgin 6 BR measurement as well. I agree, it seems both my chamber is slightly long and the chamber for the 250 pc was short.

If it's of any use, I also have a .330 comparator and a .375 comparator and measured a piece of fired brass. My .330 comparator measures 1.1805 and my .375 measures 1.1585. If you happen to have both of those comparators that might take out some of the uncertainty about whether it's comparator variation accounting for the difference in our measurements.

If your chamber is about 0.004 long and you have that shoulder touched up by a smith, you could both bump back your current brass as well as fireform the new lot of brass. Shoulder would move forward about 8 thou on the new brass which is not a ton.

The other option (and one I would consider) is simply to sell the new lot of brass, keep running your current 300 pieces of brass until the barrel dies, then when you get a new barrel make sure it's chambered properly and start fresh with new brass. That's probably the cheapest option if you can get by on 300 pieces. You could also cancel the PTG order since who knows when you'll get that (google PTG customer service).
 

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