R700 Lug Rub (outer)

[FoxSpotter]

I reckon if the barrel comes off I'll still be able to see the lug rub the thread.
It's a 26inch full bull..so There is hope there.

If the case heads are deforming to flatten on the bolt face, surely I'd be able to measure this. I do have a 21C concentricity gauge.

I'm suspecting the action was never trued, and the barrel is concentric, but the bolt nose relief cut was not enlarged beyond normal size to accommodate the 1. Wonky bolt raceway. 2 wonky action threads.

Maybe I could put some marker on case heads and run them through the action to check?