The "P" on the barrel and the "P" on the front of the receiver ring are the standard Springfield Armory marks, indicating the parts had been tested with Proof Loads.

Receivers and barrels were proof tested before being assembled into arms. Barrels were proofed before being rifled.

Receivers received stamped markings and serial numbers after heat treat.

Numbered/completed receivers went into 'parts' bins', and were pulled out (kind of) randomly for assembly, hence the difficulty in exactly dating Krags by serial number.

Completed Krags underwent a final proof procedure and received the 'circle P' stamp on the stock. (Description attached).

The U.S. government paid a royalty on each Krag-Jorgensen that Springfield Armory manufactured.

I do not know why your receiver appears 'unnumbered'.

FWIW - Possibly, the number was skillfully removed (or filled in with weld) and re-contoured by someone?

Maybe, a Springfield Armory worker stole a receiver, prior to numbering, and took it home in his lunch-pail to build his own Krag?

It was a 'Special-Ops Krag', used in an undocumented secret mission? (Joking).

Several S.A. workmen and inspectors screwed up on a Monday morning and stiffed the Norwegians?

(I am skeptical of the prototype thing).

It boggles the imagination and probably makes you a Felon! (Just kidding).

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