Picture below = like dwelltime issue. The gun is attempting to jerk the case out of the chamber under full pressure will cause below pict.
Shoot the same load with the gas block completely turned off meaning no gas to run the action and see if it still does that
Brass destroying case swipe!
unless you’re running in a World War III combat scenario, you should have an adjustable gas block on an ar 10.
-check head space w/go/no go gauges.
- check brass growth after being fired (hopefully not all your cases are chewed up like that because that makes checking brass growth extremely difficult)
assume everything is broken!