British Proofmarks

[Austin J Hawthorne Jr.]

Not wanting to hijack Bruces thread I thought I'd start another one. Among the various Birmingham proofmarks on my 1881 W.C. Scott Hammergun is one that I can't identify. It is a Crown over an S.
Also, on the barrels, are the marks...16B 18M on the right barrel, and 16B...17M on the right barrel. Would the (M) marks indicate choke ? All these proofmarks are on barrels (not the barrel flats). Can anyone familiar with British shotguns help ?
Thanks in advance.

[Bob Brown]

Are you sure it isn't a stylized, interlaced, BP cypher under a crown rather than an S? That's the Birmingham black powder provisional proof mark. It's usually just up the barrels an inch or so from the flats and often stamped deep and hard to read. You're right about the 16B 18M being the bore and muzzle diameter.

[Austin J Hawthorne Jr.]

Hi Bob,
It's unquestionably a large, deeply struck, S under a crown. I would post a photo of it if I could. There are 2 deeply struck symbols about 1 inch up from the barrel flats that appear similar to the ones on Mr. Brunner's Rudd gun.

[Bob Brown]

Yeah, the stamp doesn't look like a BP, but I'm pretty sure it is. The marks on the Rudd as well. Take a look at this image. The first proof mark in the third row from the top is the Birmingham black powder provisional proof. It looks more like an S when deeply struck. If you take a look at pictures of barrel flats from that time period on the net you'll see some that give a clearer image of the stamp. I could be wrong though. I've got 2-3 dozen British guns from that time period with those marks. The BP provisional proofs on some are clear, and others look like an S or are pretty much unreadable.

[Bob Brown]

Here is a better chart with the date ranges on it. On shotguns Birmingham used the second in the string of marks as the provisional black powder proof. I don't recall seeing that mark anywhere other than the first inch or so of the barrels.

edit: Not that it should matter on your British gun, but the French (St. Etienne) black powder superior definitive proof mark, the German shotgun proof mark, and the Danish proof on Sjogren shotguns were all crown over S at different times.

[Austin J Hawthorne Jr.]

It seems we have a mystery here. The mark does not match up to any of the proof marks in the above chart. In fact, the "S" is about the same size as the crown, looking similar to the size ratio of the 1904-1925 marks.