When is cratering not really cratering?

[Red Ryder]

Was down at the range yesterday and was talking to a guy about what appears to be mildly cratered primers from a 264 Win Mag. He said that if the hole that the firing pin slides through is a little too large, primers can appear to be cratering when in fact, they're not. I was using a load that's about 1.5grs under maximum according to the Sierra book along with 140SMKs. I intended to bump the bullets about .010 off the lands. There's no indication the primers are flattened, there were no extraction problems, nor were there bolt closure problems. I was using IMR-4831 powder and Remington 91/2 Magnum primers and Winchester brass measured to 2.490 +/- .002. The first three shots were the best I'd ever gotten out of 264 .(22w x.28h) the other two shots were flyers due to my mental collapse at having a great three shot string going.

What do you think about his statement?

Your experienced answers are appreciated.

 

[Downzero]

Re: When is cratering not really cratering?

I don't think you have anything to worry about. It sounds like you have an accurate load. Run with it.

 

[9H_Cracka]

Re: When is cratering not really cratering?

When the gap between the firing pin and FP hole is too big. I have loads that are fine in my ARs that show "cratering" in a 700 bolt gun. I may get it bushed.

 

[runngun]

Re: When is cratering not really cratering?

I get it with my Remington with all factory loads and hand loads, even 2gr below max. I don't worry about it and just look for flattened primers, ejector marks, and stiff bolt.

 

[918v]

Re: When is cratering not really cratering?

Mine craters with factory ammo as well.

 

[glock63]

Re: When is cratering not really cratering?

My SPS tactical had the oversized FP hole and showed cratered primers. It bothered the hell out of me so I had it bushed.