^ 6BRA

[old shaky]

I`ve been working with a 6BRA last few months, and it`s driving me crazy! PIERCED primers all the time! Started off fireforming with 29.6-29-8 Varget and 29.3-29.6 H4895. 105 and 109 bergers. Tried CCI BR4,Federal 205 and 205m`s. Velocity in the 2800 range. SD`s in the 3-7 range( 10 shot groups), accuracy in the.2-.6 range. 20-=30 % pierced or bubbled primers. Tried seating into the lands 30 thousand, not really any difference. After fireforming, I`ve been trying 30-30.5 H4895, 31-31.5 Varget, 10 thousand jump, same primers. SD`s a bit higher -4-8. Velocity-2880-2925. I`m still getting protruded primer and pierced primers 30 % of the time. Impact action, Insite barrel, sizing shoulders back 1-2 thousand.The BR4`s are better than the Federals, but it`s still a problem. Help! I`m tired of replacing triggers!

 

[Steel head]

My guess is a fat firing pin or sloppy fitment to the bore.
Consider getting your pin reduced and bolt bushed.

 

[Tokay444]

Got any pictures of primers that haven’t been pierced?
Are you sure the brass is fully formed to chamber length before bumping shoulders back .002”?

 

[anotherwannabe]

Pierced primers mean you either have way too hot a load or your headspace is excessive. Your loads are hot like most guys, but not excessive, so I’d check your headspace issue.

Can you close the bolt in a 6bra go guage? I’m guessing you can if you’re blowing 30% of fireforming loads. That said - you’re also fireforming a grain and a half higher than a lot of guys.

If you have stainless shims or scotch tape, see how many layers you can put on the back of a fresh case and still close the bolt. I’m guessing your chamber is too deep so you’re blowing primers and also not fully forming the cases as a result. Then you blow the primer next time because yours shooting cases that aren’t fully formed with a hot load.

 

[old shaky]

My guess is a fat firing pin or sloppy fitment to the bore.
Consider getting your pin reduced and bolt bushed.

next step

 

[old shaky]

Pierced primers mean you either have way too hot a load or your headspace is excessive. Your loads are hot like most guys, but not excessive, so I’d check your headspace issue.

Can you close the bolt in a 6bra go guage? I’m guessing you can if you’re blowing 30% of fireforming loads. That said - you’re also fireforming a grain and a half higher than a lot of guys.

If you have stainless shims or scotch tape, see how many layers you can put on the back of a fresh case and still close the bolt. I’m guessing your chamber is too deep so you’re blowing primers and also not fully forming the cases as a result. Then you blow the primer next time because yours shooting cases that aren’t fully formed with a hot load.

Thanks guys, I`ll check that next.

 

[Lilja Riflebarrels]

Try some CCI 450's. Thicker cup might help with your piercing issue. Really only other option is bushing the bolt. Piercing a primer is almost always a firing pin issue. Either your firing pin is to flat or to pointed.

It's definitely not excessive headspace. Excessive headspace wouldn't cause pierced primers. (Granted, I'm talking a couple thou, anything more then yes, it could be the issue. But I doubt it.)

 

[22-Dasher]

Try some CCI 450's. Thicker cup might help with your piercing issue. Really only other option is bushing the bolt. Piercing a primer is almost always a firing pin issue. Either your firing pin is to flat or to pointed.

It's definitely not excessive headspace. Excessive headspace wouldn't cause pierced primers. (Granted, I'm talking a couple thou, anything more then yes, it could be the issue. But I doubt it.)

BR4’s have the same thickness as the 450’s

 

[shoot4fun]

I`ve been working with a 6BRA last few months, and it`s driving me crazy! PIERCED primers all the time! Started off fireforming with 29.6-29-8 Varget and 29.3-29.6 H4895. 105 and 109 bergers. Tried CCI BR4,Federal 205 and 205m`s. Velocity in the 2800 range. SD`s in the 3-7 range( 10 shot groups), accuracy in the.2-.6 range. 20-=30 % pierced or bubbled primers. Tried seating into the lands 30 thousand, not really any difference. After fireforming, I`ve been trying 30-30.5 H4895, 31-31.5 Varget, 10 thousand jump, same primers. SD`s a bit higher -4-8. Velocity-2880-2925. I`m still getting protruded primer and pierced primers 30 % of the time. Impact action, Insite barrel, sizing shoulders back 1-2 thousand.The BR4`s are better than the Federals, but it`s still a problem. Help! I`m tired of replacing triggers!

There are a couple of good suggestions here but I'd be interested to know (no one asked) what brass you are using and how much shoulder bump are you using once you think the brass is fire formed to your chamber?

 

[Travis224]

I had a rifle that pierced primers way too easily I thought. I looked at the firing pin protrusion..it was too long. I lightly ground it down and all my issues went away. I'd start there as its easy.

 

[Lilja Riflebarrels]

BR4’s have the same thickness as the 450’s

Yup you are right, for whatever reason I had it in my head he was using 400's. More than likely it's his firing pin.

 

[never_summer]

How many have you popped at that pressure? You might have washed your firing pin and channel.

 

[old shaky]

Thanks guys, I`ll check that next.

 

[old shaky]

Thanks for all your helpful advice. The Hide is the best for no BS tips. Looks like I was doing everything right, AFTER the damage was done to my firing pin and boltface! Got a new firing pin and bushed the bolt. Hopefully, I`m good to go. Now if I could just find a mag that feeds these stubbies!

 

[SourGrapes]

What mag are you using? I was thinking about trying out 6bra on my tl3 and have been looking at mag options.

 

[Mississippi327]

If you haven’t already get a bore scope and check for carbon ring this is normally this issue when I hear pressure in any br variant. There’s no way to know if you have one without a scope and no real good way to know you got it cleaned out without it either.

 

[old shaky]

What mag are you using? I was thinking about trying out 6bra on my tl3 and have been looking at mag options.

AI with both PVA and Primal Rights kits. Not good. Best so far is the Magpul polymer, but it’s not 100%.

 

[old shaky]

If you haven’t already get a bore scope and check for carbon ring this is normally this issue when I hear pressure in any br variant. There’s no way to know if you have one without a scope and no real good way to know you got it cleaned out without it either.

Done

 

[old shaky]

How many have you popped at that pressure? You might have washed your firing pin and channel.

Yes, I did!

 

[old shaky]

There are a couple of good suggestions here but I'd be interested to know (no one asked) what brass you are using and how much shoulder bump are you using once you think the brass is fire formed to your chamber?

Lapau and 1-2 thou bump

 

[Krob95]

If you’re running AICS mags, the MDT BR mags are awesome. They worked awesome for me with my impact, no feeding issues ever

 

[old shaky]

Ya, I’ve heard they work, but can’t get any, huge backlog.

 

[LongRangeActual]

Interesting thread, I've been having the same issue with mine. Also on an impact. I'm running the 110 ATips with 4895. Pressure out of the gate. Backed it down .8 grains and got through 150 rounds without an issue.

Picked a load out of from my ladder test, one full grain under my pierced primer in the test. Went out and was shooting the same speed that it's piercing primers at the charge that was once over a full grain under that pierced primer. My guess is my barrel happened to come on after the ladder test.

I'll be trying 4350 tomorrow to see how this plays out.

 

[bpair]

I sent my Impact bolt over to SAC for their firing pin service to reduce the size. 223Ackley at nowhere near pressure was piercing primers, not any issues after getting the bolt back.

 

[anotherwannabe]

4895 is too fast for 110’s (and 109’s). i suspect you’re all way over pressure.

i’m surprised that everyone is jumping to the conclusion this is a bolt issue with impacts. granted i’ve only seen one on my bench but there are tons of guys shooting br based dashers and bra’s with impacts and not blowing multiple primers at 200 round matches.

has anyone sent their action back to tate with this symptom? i’m sure he would want to measure it up.

 

[LongRangeActual]

4895 is too fast for 110’s (and 109’s). i suspect you’re all way over pressure.

i’m surprised that everyone is jumping to the conclusion this is a bolt issue with impacts. granted i’ve only seen one on my bench but there are tons of guys shooting br based dashers and bra’s with impacts and not blowing multiple primers at 200 round matches.

has anyone sent their action back to tate with this symptom? i’m sure he would want to measure it up.

I chopped it up to over pressure also. Switched it up to 4350 and all is well.

 

[kthomas]

Interesting that you are having feeding issues with AI mags and feed kits. You may have to adjust the feed lips a bit to optimize feeding.

I'm currently using MDT 6BR mags in both my 6BRA Mausingfield and my wife's 6BRA LP Fuzion. No issues, but didn't have any issues either with AICS mags + Primal Rights mag kits either.

And you're not the first person I know that's found pressure early in an Impact 6BRA.

 

[Yankee88]

4895 is too fast for 110’s (and 109’s). i suspect you’re all way over pressure.

i’m surprised that everyone is jumping to the conclusion this is a bolt issue with impacts. granted i’ve only seen one on my bench but there are tons of guys shooting br based dashers and bra’s with impacts and not blowing multiple primers at 200 round matches.

has anyone sent their action back to tate with this symptom? i’m sure he would want to measure it up

It’s not crazy to not rule out the impact actions since people coming forward so far with this issue have impact actions.

If it’s only a pressure issue, would there be other indicators, such as on the brass?

 

[Smokin7s]

P

next step

Please check everything else before you let the same guy that chambered it mess with an impact action, if anything call tate.