Thoughts on a case head picture

[trotterlg]

This is a fired case from my cheap 17-204 Savage Axis build. Except for the barrel it is stock, load is 28gr of Winchester 760, Remington 7 1/2 primers and Nagel 30gr bullets. A load of 27gr looks exactly the same. No hard bolt lift, primer pockets are still good. I am thinking the primer is flowing into the space around the firing pin more than a crater, I have not pierced a primer or had any other problems. The gun is shooting better the faster it goes, I am wondering about going up to 28.5 or 29? What do you think. I am happy with the accuracy, but it is a go fast round so I would like to get the most out of it, if I wanted slow and easy I would have gone with a 17 Rem FB or a 20 Vartag. Larry

[Bill K]

Looks okay, so far. If you do try to raise the powder charge, I would only go 1 to 2/tens of a grain and be very careful and watch for any pressure signs.
Safety first, speed last. Bill K

[Oleman]

What Bill said.

Damn next time you go south Larry take some of this damn rain with you they need it down there!

[Nor Cal Mikie]

IMHO, First thing that comes to mind is a headspace issue. Not a rifle problem but more like the case is too short for the chamber and when the round is fired, it gets pushed back against the bolt head and sometimes the primer will back out a bit and you'll get the same dished primer effect.
If you take that fired brass and neck size only and reload, my bet is you won't be seeing any problems with the primers getting dished like that. And when you resize, make sure you don't push the shoulder back too far and end up with the same looking primer.
And like Bill said, if you're planning on going up in powder charge, go easy.

[Chuck Miller]

Sure looks like my rems before Gretan bushed the firing pin hole

[trotterlg]

That is why I think it is just a loose firing pin hole, the head space is near zero, I set it with a sized case at zero and it only has the slack in the threads when I tightened the barrel nut. 27gr of 760 is max in a 17 Rem and this case has more capacity by a few, I guess I need to see how much it will hold and ask someone with quick load to do some calculations. It just seems to shoot better the faster it goes, but then it may be just getting the barrel broke in, so all this may not mean a thing. Larry

[Nor Cal Mikie]

I have 5 different Savage builds and not one has ever had a problem with a loose firing pin hole. It's easy to throw more $$ at it when it's pretty simple to check your brass size to see if in fact that's the problem. Calibers from 20 VT and a "short" Wildcat all the way up to 6.8 SPC and a few in between.
If the brass moves in the chamber when fired, you'll see that kind of results showing on the primers.
Not one of my rigs will shoot factory ammo because I set and keep the headspace on the snug side. No room for the case to move and the brass gets sized and the shoulders bumped maybe .001 to .002. Body size if the bolt gets hard to close. Brass lasts a long time that way too.
It's your rig but if it was miine, I'd be checking the brass before I started throwing $$ at it. YMMV, Mike.

[GeorgeL]

Primer is not backed out indicating headspace is fine. In general, I tend to see a flattening of the primer as loads get (too) hot. It appears the corners of your primer are still rounded and haven't yet begun to flatten. I think the primer flow back is due to too much firing pin hole/firing pin clearance rather than pressures too high.

[george ulrich]

Originally Posted by GeorgeL

Primer is not backed out indicating headspace is fine. In general, I tend to see a flattening of the primer as loads get (too) hot. It appears the corners of your primer are still rounded and haven't yet begun to flatten. I think the primer flow back is due to too much firing pin hole/firing pin clearance rather than pressures too high.

yep exactly right primer backing out due to excessive headspace will FLATTEN primer not cup at firing pin. check clearance and size....

[Nor Cal Mikie]

George & George:
Could be both, hot load and or primers backing out. If it was me, I'de be checking brass for size compared to chamber THEN go from there. Everybody wants to blame the rifle and throw $$ at it when in may be as simple as brass sizing. Been there, seen that on my own rigs. Need to start somewhere.