I have a 12 gauge side by side made by Robert Jones of Manchester Street, Liverpool England. Here is a photo of the proof marks:



From a PDF of proof marks I got off the Internet, the marks indicate:
The crown with NP below indicates it is "Definitive Nitro Proofed for All Guns" and the crown with BV below means it's a "View Mark" (whatever that means) and both have been in use since 1904. The crown with BNP below indicates it "Definitive Nitro Proof for Barrel and Action and has been in use since 1954. All marks come from the Birmingham proof house.

Now from these is it possible to date the gun? For instance was the gun reproofed after 1954 or were all the proof marks added at the same time? Also, any idea what the other markings mean?
Thanks
Alan

It was re-proofed after 1954 as you say but for some reason they ommitted the Crown over R mark to indicate that. Lagopus.....

It was reproofed in 1982. The mark at the lower left is the Birmingham date mark. The "HB" indicates 1982 and the "1" indicates the seniority of the examiner, "1" being most senior. Note that from 1975 to 1984 the date mark used was a circle and not the crossed swords.

As Lagopus stated there does not seem to be a reproof mark.

Why are there 3 seperate stamps indicating nitro proof?

Original proof at "13" or .710 . Reproof at .719 . No need for the reproof stamp when the proof marks supercede the earlier ones .The original proof bore both NP and the words NITRO PROOF . LOoking at the photo I would suggest getting the lumps checked as the green gunge around the braze can be a indicator of failing braze.

Ian
I didn't notice the HB over 1 inside a circle. I assumed (incorrectly) that the stamps on both sides of the lug were the same. Is it possible to determine the original proofing of the barrel? What does the 12 over a C inside a diamond, the 13, and the .719" refer to?
Thanks
Alan
OBTW, you said there doesn't seem to be a reproof mark and yet you indicated that the HB over 1 inside a circle says it was. Confused.

I found this from the Birmingham Proof House website:


I assume my gun was proofed sometime between 1925 and 1954 as the marks corresponds with the ones used from 1925 up to 1954?

Proofed prior 1925 but after 1904 . 12 in the diamond indecates the bore size as in it is chambered for 12 bore cartridges .

Thank you gunman/ER..I did not know that there was that bit of redundancy on the original proofs.

English Rebel, 13 indicates that the original bore diameter was .710. .719 is the bore diameter as reproofed. As gunman says, the original proof is in the 1904-25 period. This is a bit tricky, but 1925-54, the gun would show chamber length. This one does, but the chamber length stamp of 2 1/2" and the 3 tons stamp are so similar that it's obvious they're from the same set of proof stamps, which are the later ones. So with no chamber length stamp among the original marks, that means it does not fall in the 25-54 perid.

One note on the 13. It has been stated that the 13 indicates an original dia of .710. this is not entirely correct. In that era bores were simply checked with a series of plug gages & marked according to the largest one which would enter to a depth of 9" from the breech.
A 13 gauge plug diameter is .710" while next step up of 13/1 was .719". When this gun was proofed it accepted the 13 plug but not the 13/1. Actual diameter could have been anywhere in betwen.
The .719 mark at the re-proof does as I understand it mean an actual diameter of .719" by measurement. It may not have taken much honing at all to go from the 13 to the .719" bore.This may well have been done in preping for the re-proof.

Piper , you are correct. The bore would have been plugged with a set size gauge ,if it entered passed 9" ,a gauge of the next size up would be used. If this did not enter passed 9" then the barrel would be marked at that size.So yes it would have been possible to have a barrel proofed at .719" but it in fact would have measured as .727". Gun makers would therefore try to bore as close to size as possible . The problem was highlighted with the impottation of guns like the Miroku in the 70's ,being metric size 18.4mm and 18.5mm [,724" & .728"]new guns that actualy measured .728" were stamped at .719" therfor being only .001" in proof.They then started to use an intermediate plug and marked to the next size up ,so it is possible to find Miroku's that are stampped at ,729" that actaly measure at .726".
With going metric they with increments of .004" .01mm bores are marked to the nearest lower size .
If you think you guys have problems with all this ,think how we feel ,we have had 6 changes to the rules ,marks and measurement since 1904.

Appologies over the spelling etc.I pressed submit instead of preview.I think it makes sense .

And here we thought you Brits did it just to confuse us Yanks.

WOW this is really interesting. I didn't know so much information was in those stamps until I started this thread. So to sum up, my gun was made sometime between 1904 and 1925 and then reproofed in 1982. It is in remarkable shape for a gun that is that old (although it could have been refinished sometime in its life.
Thanks for all your help.
Next question is what is its value. I think I paid around $400 for it plus shipping and import costs -- probably $600 total cost.
Alan

Value is hard to determine without additional photos, or at least a good description of condition.