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Can I get some help with cratering?

IMG_0092.JPG Im kinda bummed at this. I got a great shooting load in a 6.5 creedmoor using imr 4451 and 140 eld. Es/sd look great and 1/4 moa for the most part. 4451 worked great when you step on the throttle. Id rather not post the grains but its nothing outrageous. Velocity is 2755 avg, 26" savage. No sticky bolt either. But this is what scares me, should I be worried?
 
I suspect your firing pin hole is too big. Primer doesn't look at all flattened. Can't see an ejector mark.

What rifle?

Savage lrp. I get nervous sometimes using lapua brass and 7.5 primers since thats a tough combo. Im 1 gr over posted max. One thing I did just notice is that this lapua brass my primers seat rather deep so it gets a " run" at it if that makes sense.
 
Get your firing pin hole bushed. I had to do it on my Savage F/TR when I went to small primer .308 Palma brass. It is basically the same action as you have, only single shot.

GreTan Rifles can do it, among others.
 
One thing I did just notice is that this lapua brass my primers seat rather deep so it gets a " run" at it if that makes sense.

Not sure what you mean. The firing pin?
Also "...seats rather deep..." Seated means to the bottom of the primer hole which is where you want it. I'm sure it is not (.055) 55 thousandths below flush!
 
Not sure what you mean. The firing pin?
Also "...seats rather deep..." Seated means to the bottom of the primer hole which is where you want it. I'm sure it is not (.055) 55 thousandths below flush!

Haha sorry wife was talking to me as I was typing. The primer sits about .011-.012 below the surface of the shell in the pocket. So when it fires the primer kinda gets a running start at smashing into the bolt face.

Edit: best way to describe it is my primer pocket uniformer doesnt even come close to touching the seating surface. Unlike say my 223 lapua brass ill get a nice full cleanup
 
Yeah, wipe your finger over every primer seated before you place the case in the loading block and you'll get a feel for the pressure required to seat them just below flush. Too far and you'll upset the anvil and risk misfires. Menial task priming but one you need still concentrate some.
As Dusty says you're worried about a non issue as it would seem by reading the primer that pressures are still only moderate.

Some rifles and primers crater worse than others but sure, just keep an eye on it.
 
Good info, thanks everyone. Im gonna check depth w drop indicator and mic a primer and see whats goin on. This could really affect es/sd right? Might explain some issues ive been having.
 
Well u guys were certainly right! Measure .1233 for primer and .1244 on pocket depth. Ive been crushin the hell out of these things all these years. Learn somethin new everyday, thanks so much guys
 
The cratering on your primers doesn't look very bad.
Yeah it's a crater, but you're not getting any blanking (otherwise you would of told us about it).

Change to CCI-450 or CCI#41 (same as 450 but even harder cup).

I get cratering on my R700 223. It's not a big deal unless other problems arise.
 
I might measure the firing pin hole that goes through the bolt face - like is it too big? If so, a bushing having a smaller hole might fix the problem, if in fact, that is the problem.

My guess is the primers have little difference in actual hardness but vary in wall/cup thickness. For example, cup thicknesses for CCI 450's, BR4's, Rem 7 1/2's are .025". I would also guess (really don't know) that CCI 41's measure .025. Other small rifle primers of varying makes intended for standard use have cup thicknesses of .019 - .021.

I was made aware of this when the ultimate primer crater event occurred when I was shooting speedy .17 Remington loads when I had a FTF after some 5 rounds fired with Winchester SR primers. These loads previously worked just fine with CCI 450's. What happened was the chunk of the primer punched out by the crater event went inside the bolt & blocked the firing pin. I cleaned out the near perfect size firing pin hole with a pipe cleaner and went back to the 450's and had no more problems with normal and expected .17 Remington performance.

Now, I use nothing except CCI 450's & CCI 41's & Rem 7 1/2's for all my rifles that use small rifle primers because they all have relatively high pressures.

I have a lightly used Lilja .17 Rem barrel (no rifle) threaded for a Ruger M77 MKII that I would sell real cheap , if interested send me a PM.
 
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There was a thread on another forum about cratering in a Savage. The suggestion was to get a new bolt head from PT&G along with a firing pin to match. You can get the bolt head and firing pin for about the cost of bushing the bolt head you have, but your rifle won't be down for the repair. Note that you will need to at least check head space if you get a new bolt head, possibly have to reset the head space.
 

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