deciphering proof marks

[Licensed to kill]

I have been searching the net for awhile to get info on these proofs but to no avail. A couple look similar to Birmingham proofs but not quite the same. Specifically, I am interested in the proof house, war of manufacture and most importantly, if it is nitro proofed. The guy I bought it from said it was reproofed for nitro relatively recently (like the last 50 years) but the only thing I can see that MIGHT represent a "nitro" proof is the "NP" but that stamp looks to be as old as the others AND I am not going to "assume" that it means nitro proofed especially when most (all?) others I have seen actually SAY "Nitro proofed". Anybody know what I have here?.

 

[jamesharrison]

IF it was sent in & passed re-proof, it would be marked to allow you to date the re-proofing, at least if it was sent to Birmingham or London. Because of the 70 on each barrel, I am going to guesstimate someone re-chambered it for 2 3/4" shells [= 70mm], proofed for 1/2 ounce [1/2 OZ]. I would also guess that the NP marks on each barrel does in fact represent Nitro Proof, at least according to whoever did it.

HOWEVER, the 1855 to 1875 Birmingham proof marks evident on the barrels would NOT have any metric markings whatsoever!!! It is likely that some "gunsmith" opened the chambers & did the later stampings at some later point in time, but it was NOT done by one of the 2 English proof houses. Because it is not a muzzle-loading gun, it post-dates 1861. In addition, because there is no indication of choke, which was not done in Britain before 1875, we can tighten up the date of manufacture to 1861-1875, which match most of the original Birmingham proof marks.

That said, the one mark that is missing on the barrels for the period is the gauge / bore marking.

None of the other marks match either Birmingham or London marks in their entirety, in any period.

 

[BigUglyMan]

I was talking to Jonny Carter about doing a video about proof marks. Based on our conversation, I think we can anticipate a video once Holt's gets some inventory built up for their next sale.