Ruptured Primer

[mark501w]

I don't believe those gauges check mouth dimensions only headspace.

[CK_32]

Dang I thought semis had less pressure than bolts.

Your have one tight little chamber. My 700 is running around 45.6 of varget behind a 175 smk.

Like above I'd drop the powder a bit and find a lower node. But grab a chrono and watch for squibs when you drop in powder charges. And just think of it this way your powder supply will last longer

[mark501w]

Pressure is pressure I'am not familiar with these alternate forms of chambering . I don't know how low you can go with Varget. Since it's a stick they are usually pretty flexible. Got any win ect. Cases.

[LynnJr]

Primer cratering is caused by more than just high pressure loads.

If your firing pin hole is large you will get cratering because the primer isn't supported allowing it to flow back into the boltface.

Likewise a weak firing pin spring will often times show up as cratered primers.

You will often times see guys bushing there firing pin holes to a smaller diameter in order to avoid cratering and piercing problems.

Do you get any fail to fire rounds do to a soft hit?
Do you have any calipers handy?

[zomie]

I am just going to put this out here ...

Winchester recently had a set of bad primers. A friend and I had some from the same lot and experienced similar issues. Him in a 6.5x55 and I in a 308 loaded hot but not nearly at the top end.

I guess I am bringing this up to be careful Winchester took the load back replaced them and also replaced the bolt.

[mark501w]

what bothers me is the ejector is showing up on the case face that's pressure.

[LynnJr]

Ejector marks are also common with excess headspace associated with semi-auto's.

[tigerfu]

I think your loads are too hot. All 3 casings show significant primer cratering. With tight firing pin hole, this is definitely sign for high pressure. Also the case heads have ejector impressions, which is another textbook high pressure sign.

Did you chronograph your loads? It should have given you indication already.

Tula NATO primers are pretty hot. They are magnum equivalent and I usually have to decrease powder charge by 5% to compensate. When used with surplus brass at Max load, it may push you over.

-TL