Pressure signs?

[bradworley]

Pretty sure I'm getting pressure signs on the last 2 on the right, but 2nd from the left I'm not sure about?
Tikka t3 varmint 6.5CM. 26in. barrel
147gr ELD match bullets
Lapua SRP case, 2nd firing, CCI 400 primers
H4350, from left to right - 41gr, 41.5, 42, 42
The 41gr had no noticable signs and didn't group for shit. But the 41.5gr was .4 MOA with a 10 shot group.
The 42gr was immediately noticable. I could feel the jagged crater on the primer.
But once I got home and started to inspect the 41.5gr cases, I noticed a bit of cratering on them as well.
Opinions?

 

[straightshooter1]

Pretty sure I'm getting pressure signs on the last 2 on the right, but 2nd from the left I'm not sure about?
Tikka t3 varmint 6.5CM. 26in. barrel
147gr ELD match bullets
Lapua SRP case, 2nd firing, CCI 400 primers
H4350, from left to right - 41gr, 41.5, 42, 42
The 41gr had no noticable signs and didn't group for shit. But the 41.5gr was .4 MOA with a 10 shot group.
The 42gr was immediately noticable. I could feel the jagged crater on the primer.
But once I got home and started to inspect the 41.5gr cases, I noticed a bit of cratering on them as well.
Opinions?

It doesn't necessarily look like cratering on those primers due to pressure. It's very likely just from the space between you're firing pin and the firing pin hole in the bold face (not unusual for factory guns). For some people's guns, it's more pronounced and will have their bolt face "bushed" so there's very little space there and no more false pressure signs like that.

The primers look fine to me, as they're not really flattened much (still showing rounded sides on the circumference). I see no other pressure signs on the base face. Along with this, you're not reporting any stiff bolt lift. All in all, I just say you've got no pressure signs, yet.

 

[bradworley]

It doesn't necessarily look like cratering on those primers due to pressure. It's very likely just from the space between you're firing pin and the firing pin hole in the bold face (not unusual for factory guns). For some people's guns, it's more pronounced and will have their bolt face "bushed" so there's very little space there and no more false pressure signs like that.

The primers look fine to me, as they're not really flattened much (still showing rounded sides on the circumference). I see no other pressure signs on the base face. Along with this, you're not reporting any stiff bolt lift. All in all, I just say you've got no pressure signs, yet.

Thanks! Ya, bolt lift was fine. I was just a bit concerned because Tikkas are known for being hard to read pressure signs and 42gr seems to be the max load listed across all the manuals I have.
I'll probably stick with 41.5 since it was grouping great anyhow

 

[918v]

CCI 400 primers are soft so any cratering is meaningless in this application.

 

[M4orturnate]

Definitely would not use cci400s for this application. Youre asking to pierce one. 42g is on the high side but depending on chamber could be ok. I find between 41.2 and 41.7 to shoot the best with good sd

 

[bradworley]

Definitely would not use cci400s for this application. Youre asking to pierce one. 42g is on the high side but depending on chamber could be ok. I find between 41.2 and 41.7 to shoot the best with good sd

Ya, I was thinking about picking up some 450s to test with, but I have so many 400s it's hard to not want to use them.

 

[M4orturnate]

Ya, I was thinking about picking up some 450s to test with, but I have so many 400s it's hard to not want to use them.

Theyre usable id just drop the charge a grain or so. Theres a good accurate node around 40.2 if i remember right.

 

[Pharmseller]

I don’t look at primers much as a pressure indicator. And by much I mean not at all.

Excessive velocity, ejector marks, and/or sticky bolt lift are my indicators.




P

 

[BearNaked]

like others said, primers are not reliable pressure signs but those still have rounded edges and no bolt swipe. good to go.

i would go more off of bolt lift feel and swipe.