Re: 1903 Springfield Mk 1
Raritan was a major storage depot and shipment point for weapons of all kinds being shipped to the ETO. Later, it was a shipping point for rifles being sold through the DCM to civilian NRA members. Under the rules in effect at that time, every surplus military rifle sold to anyone had to be inspected and proof tested; the RA-P mark indicates that that was done. The confusion comes in because that mark was also used on rebuilt rifles after inspection and proof testing. Many thousand brand new M1903A3 rifles were shipped from Raritan to NRA members in the 1950's and 1960's. They had never been needed and had never been issued, but many folks assume they are rebuilds because they have the RA-P marking.
There is some dispute about the actual meaning of the mark. I had long been told and believed it stood for Raritan Arsenal - Proved. But some evidence indicates the P stands for Peterson, an arsenal inspector.