I really think someone tightened down the barrel band just to hold it in place.  Threads on barrel are good, never loctited, or welded to the reciever.  I was able to get the barrel to nearly time correctly on three different stripped receivers, with all headspacing correctly (closes on Go gauge but not on the No-Go gauge).  There is range between 1/64 - 1/16 inch in additional space I could try turning the barrel to fully torque it against the inner shoulder of the receiver since it is currently hand tightened.  The muzzle erosion gauge just barely touches 0.3005 and I noticed the barrel was marked with a "P".  Does the "P" mean anything?  I can only speculate it could mean "Proofed." 

How much torque should I be aiming when torquing the barrel?  Would a Wheeler action wrench work, with universal head, for the Krag?  I have a wood lined barrel holding fixture I used to remove Mas 36 barrels.