I believe Mark said there was a "P" on the receiver ring, which makes this whole circumstance more curious.

You would think someone should have noticed things were not quite right prior to heat-treat. Possibly, this is revealing of the speed and volume of the work at SA!

I bet someone got yelled at in the Hill Shops! A lot of effort went into reducing that 6 and 1/2 pound forging into an almost finished receiver.

Hey, 119 out of 120 operations ain't bad.

I doubt that Mark's Krag was completed into a finished arm at Springfield. I doubt it was ever sold by the DCM.

It seems plausible it was salvaged by one of the surplus dealers, who bought the Armory's obsolete parts, finished and unfinished.

'FredC's' suggestions about testing receiver's hardness are good ones.

p.s. This is fun!