Primers showing pressure signs in 6BRA?

[titus123]

So I just put together a Savage in 6BRA.... Every load I have tested all show cratered primers.... Even mild loads like 30.8 grains Varget, under a 95 grain Bergers VLD Target seated .015 off the lands, and a CCI 450 primer show the same signs.... My best guess is firing pin fitment is a bit loose. Any input would be much appreciated.
P.S.... the barrel is a 1-8 twist, .272 neck.

 

[1885Winman4590]

Hi bud, it's me again. Send bolt to Grimstod to have it bushed. Reasonably priced, fast turn around time, and beautiful work. Also vg communication. Primer cratering goes away.

 

[dfrosch]

Set the firing pin protrusion to .04. If that doesn't help, you'll probably need to have the bolt head bushed.

 

[2dogs]

I send my bolts to Gre-Tan and no more cratered primers.

 

[titus123]

Set the firing pin protrusion to .04. If that doesn't help, you'll probably need to have the bolt head bushed.

Serious question... How do you adjust the firing pin protrusion??? This is a Savage Axis action.

 

[ckaberna]

Is headspace correct? Seen this before on custom action after setting shoulders back a “little” too much.

 

[titus123]

Is headspace correct? Seen this before on custom action after setting shoulders back a “little” too much.

As far I know.... Though this is new Alpha Munitions 6BRA brass.... I didn't check to see how close it was to proper cartridge headspace.

 

[ckaberna]

As far I know.... Though this is new Alpha Munitions 6BRA brass.... I didn't check to see how close it was to proper cartridge headspace.

I would check that first. The shoulders on mine were set back about .007-.008 and somehow created this condition. Once I seated to a hard jam into the lands they did ok and blew back out. I won’t be doing that again.....

 

[dfrosch]

Serious question... How do you adjust the firing pin protrusion??? This is a Savage Axis action.

Don't know if this works on an Axis:

Savage Shooters - Firing Pin Protrusion Data.

Firing Pin Protrusion Data.

www.savageshooters.com

 

[NorCalMikie]

Is headspace correct? Seen this before on custom action after setting shoulders back a “little” too much.

BINGO!! Once the brass is fire formed to the chamber, my guess is THAT problem will go away. And forget the firing pin bushing thang. Fix the brass size problem before you start throwing more $$$ at it.

 

[titus123]

I would check that first. The shoulders on mine were set back about .007-.008 and somehow created this condition. Once I seated to a hard jam into the lands they did ok and blew back out. I won’t be doing that again.....

You Sir, are a genius.... I measured my unfired brass, against my unfired.... The difference is .004 thousands

 

[titus123]

BINGO!! Once the brass is fire formed to the chamber, my guess is THAT problem will go away. And forget the firing pin bushing thang. Fix the brass size problem before you start throwing more $$$ at it.

I just measured both fired and unfired.... Unfired is .004 thousands shorter at the shoulder, so my guess is, Excessive headspace from new brass.

 

[ckaberna]

Lol, no genius here or I would have never set those shoulders back like that. Simply sharing my experience in an effort to help.

 

[ckaberna]

I just measured both fired and unfired.... Unfired is .004 thousands shorter at the shoulder, so my guess is, Excessive headspace from new brass.

One other thing to look out for on the cases you fired , a lighter color of brass near base of case, will look like a band around the case at the .200 line. If you have them you may want to chunk them, sign of coming case head separation.

 

[titus123]

One other thing to look out for on the cases you fired , a lighter color of brass near base of case, will look like a band around the case at the .200 line. If you have them you may want to chunk them, sign of coming case head separatio n

Case webs look good. So far