They started Nitro proofing in 1891. The NAZI Eagle N is Nitro proof that was used from either 1939 or 1941 to 1945.Okay... Good to hear 500 isn't crazy. I'll probably pick it up this weekend. I don't know PPs that well but I believe the Nitro proofs and 359 waffenamts are correct. I think they started nitro proofing them in 1940?