Weird marks on primers

[PaulB84]

This is factory ammo but I figured I would ask here.

Savage 110 trail lite in 7BC that for certain boxes of ammo is incredibly hard to extract fires brass. Feeds loaded rounds fine but then has very heavy bolt lift and occasionally needs to be mortered

Are these marks indicative of anything that could help me diagnose the problem? Thanks

 

[PaulB84]

Zoomed in

 

[Thegman]

Can you post a close-up of the bolt face? Looks like there's a rough spot, at minimum, making that mark in all the primers. Not sure if that has anything to do with the difficult opening, but maybe.

But being that the 7BC is using steel alloy cases (correct?) it may be a little different in diagnosing case sticking issues such as excessive pressure, headspace, etc. I know the NAS3 cases can cause unusual issues not generally seen in brass cases.

 

[UncleNommies]

@PaulB84 im dealing with the same issue of having some rounds work flawlessly and then a random extremely hard extraction. I've contacted Federal and both boxes of ammo I have are current production! My rifle is a Tikka T3x action and Proof PXT barrel.