Many years ago worked on a 100 that had had a 250 Savage fired in it. It was a .243. Damn rifle held together! But the chamber was bulged pretty good just forward of receiver.

Only way we could get it apart was to drop a piece of steel cleaning rod down bore and tap it open. We knew what the bad cartridge was as when we peeled it off bolt face you could read 250 Sav on bolt face! Otherwise it was a fire formed .243.

Ditto on the gas system. Dirty gas piston can really cause issues! sounds like a good cleaning is in order.

Founder
Ancient Order of the 1895 Winchester

"Come, shall we go and kill us venison?
And yet it irks me the poor dappled fools,
Being native burghers of this desert city,
Should in their own confines with forked heads
Have their round haunches gored."

WS