Extractor recess flow?

[jethunter]

If you are seeing engraving marks on the bullet of factory loaded ammo, there is an issue with throat length. A chamber cast would show this distinctly.
A good 'smith needs to have a look at your rifle. The signs you see on the fired brass are pressure signs, nothing else.
Dave.

Dave is right.

It is possible you got a production lot of softer than normal brass, but if a factory cartridge has rifling marks engraved on the bullet after it has been chambered there is likely more happening here than just soft brass. First thing to do is check the chamber length with headspace gauges, then do a chamber cast to see what is going on in there. A gunsmith should look at it if you aren't comfortable doing it yourself.