odd looking primer hits...

[Ring]

260 FL'ed brass
123amax
44.3 h4350

All the other primers look fine.... Even on these you see nice round edges... No flatening..


These 6 looked like a nipple were its flowed into the fireing pin hole.. But still round edges....

 

[Temp9]

Remington action? Either way, looks like an overly large firing pin hole. Not sure why these six were worse, though.

 

[timjoebobbradley]

probably round edges on the primer because the brass is flowing around the firing pin hole. If you back your load off 1 whole g how does the firing pin hit look? I think you are looking at over pressure signs.

 

[Ring]

Ptg 700 bolt.

I've shot 150 at this load... No psi signs..

 

[oldfatguy]

What brand primers? Some are softer then others.

Just noticed mixed brass. Different brass has different volumes so what is safe in brand X might be over pressure in brand Y.

OFG

 

[jagged77]

I'd say over pressure, I've seen similar on my .223 resulting in pierced primers. If you've any left to shoot wear safety specs. Try CCI primers also, they have a harder cup.

 

[Fuzzball]

Cratered primers are usually due to a poor fit of the pin in the bolt face. Second most common reason is soft primer cups. Third most common is a weak firing pin spring. Forth most common is excessive pressure.

You need to figger out which it is for yourself and fix it soon, some of those are real close to blanking and that would not be good for your bolt. Or your face/eyes.

 

[Ring]

What brand primers? Some are softer then others.

Just noticed mixed brass. Different brass has different volumes so what is safe in brand X might be over pressure in brand Y.

OFG

remington LR

 

[Ring]

Cratered primers are usually due to a poor fit of the pin in the bolt face. Second most common reason is soft primer cups. Third most common is a weak firing pin spring. Forth most common is excessive pressure.

You need to figger out which it is for yourself and fix it soon, some of those are real close to blanking and that would not be good for your bolt. Or your face/eyes.

standard pinhole.. so by definition, not great
maybe, they are rem LR, but ive shot 600 of these in this gun so far, and in doing load testing with MAX loads, i still didnt see that much flow, just flat primers... and ejector swipes
could be week, but i doubt this gun has more than 2 k on that spring
any time i get near max in this gun, i get flat primers, this is the 1st time i have ever seen that much rear flow and not had a flat primer

 

[Fuzzball]

"....this is the 1st time i have ever seen that much rear flow and not had a flat primer "

Okay, I left one possibility out. The brass rolls primer cups are stamped from aren't precisely identical from one end of the roll to the next. Thickness and/or alloy can change but the effect will be to weaken the cup top a tad, making cratering possible with normal pressure loads. Change brands or even same brand but different lot numbers and see if the cratering stops. (I've had excellant results with Federal primers but all makers will get a flawed roll of brass from time to time.)

You should be able to get high pressure sticky cases with "normal" appearing, unflattened primers if you're not setting the sized shoulders back too much. Meaning excessively flat primers are more often an indication of poor resizing technique than excess pressure.

 

[former naval person]

Remingtons commonly exhibit that...I understand that is part of a safety concern on their part...the little that flows back inhibits the further flow preventing "blanking" and a high pressure gas leak. Cosmetic as far as you are concerned.

 

[RugerSlinger]

I had primers due the same thing to me, I found that I bumped the shoulders back a bit to far on the ones that it happened to. I was using the exact same load and it only happened on the over sized brass. Maybe that happened somehow.

Also hows the accuracy with mixed headstamp brass?