Savage 6.5 LRP cratering primers

[Wrcassell21]

Hello all, I have a savage LRP in 6.5 creedmoor, when sighting in on paper with Hornady match ammo I noticed the rifle was cratering primers, I even ran some mild loads of 39.6 of h4350 with 140 ELD at 2.80" and still had primer cratering. I did not have any heavy bolt lift nor difficult extracting or chambering rounds. I did notice when resizing though that some primer pockets were loose ( even though I had loaded some with 41.5 grains of. H4350)

There is also 2 light dimples on my bolt face

Any ideas

 

[Wrcassell21]

Primer

 

[Barrelnut]

The dimples could be caused by gas leaking between the primer and the primer pocket wall. It acts like a blow torch.

The primer looks cratered but doesn't look flattened. Usually when the load it too hot the primer will also start to flatten and not look so rounded or beveled near the primer pocket wall.

Is it possible that there was a lube like oil in the chamber? Is it a new rifle?

 

[tbrice23]

I don't see ejector marks or swipe marks on your case head in the picture , I'd inspect all other fired pieces of brass and measure your primer pockets any ones larger than .210" have definitely been over pressured.

Im assuming these are once fired brass ,correct ?

Cratering is sometimes related to an oversized firing pin hole more so than over presure. However , at sometime the past there has been a case or two that has definitely been an over oressure load fired in that chamber .

Two of my factory Savages came from the factory with "ghost ring" gas cutting on the bolt face from test firing from the factory proof loads. Im assuming you checked the bolt face for this gas pitting before you shot the rifle new.

If the pitting just happened and you are loading a light starting load and just a few pieces of brass have enlarged primer pockets than I'd bet you probably dropped too much powder in a few cases without knowing it. ???

It happens.

 

[Wrcassell21]

The gun is second hand, but I did give it a good cleaning before my load development, I also thought about an issue being a oversized firing pin hole?