Friend of mine got a brand new Savage 12 VLP in .223 and was shooting factory ammo, both some cheap PMC and Hornady 75gr BTHP Match ammo. Both types of ammo are showing pressure signs on the primers - most were cratered while a few were pierced and he had one completely blown out. He was going to call Savage today, but I thought I'd ask the collective wisdom of the THF what their thoughts were?

I would contact both savage and the ammo manufacturer.

Was he shooting 5.56 ammo in a .223?

Nope, all ammo was .223 Rem.

Also, he did a thorough cleaning before shooting and was cleaning every few shots to help with barrel break-in.

Also Part II - I shot some of his PMC in my AR and it did not show pressure signs. I'm pretty sure its a rifle, not an ammo issue.

Tight chamber issue?

Wouldn't a tight chamber be noticed when loading?

One time at Band Camp, I had a rifle that had a Firing Pin that was too long.
It was piercing Primers.

It was a used rifle, so I can't say it was a Factory Issue.

It is something to consider.

I hope you get your issue resolved.

Firing pin too long, or ammo too hot.

I think it would be unusual to go to store and buy two different brands of ammo and with different loads and get hot loads on both. Not saying it couldn't happen just unlikely. JMO