I found more pictures of reloads bearing this mark and now it is clear that the marking actually is a “VP” monogram. However, I still don’t know its meaning. Any ideas?
Very interesting Fede, but I have no clue! The only country I know that requires primers to identify the commercial loader of reloaded cases is Argentina, though these primer markings also show up in UK reloads, but I don’t know if they are required.
The only other primer marks like these are those used by the manufacturer of the primers, but again I don’t know of any primer maker who might use VP.
seen here also on a WIN casing
Here is a similar VP mark on an 1861 Colt musket w/ Amoskeag lock from 1863:
On the gun it stands for “Verified Proof” as I understand it. Perhaps it has some sort of arsenal or manufacturer-related meaning in terms of inspection for the primers then?
That Primer in the Win case looks like a badly stamped “NP” ( “Norma Projektilfabrik”: Norma regularly stamps its Primers, both Factory ammo and reloading components.)
The Other possibility is " Vhitahvuori Primer" ( very common in Europe, alongside their Powders).
Just some thoughs…