doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com William Sumner Hammer SxS - Questions

I'm in work today but have a book with Liverpool makers/retailers in, I'll have a look later.

Another example. 1888 J. Blanch reproved in 1999 (Crown over R) using Nitro Powder (according to an e-mail with the Birmingham Proof House) for; Service pressure 740 BAR = 10,733 psi; Maximum statistical individual pressure 850 BAR = 12,328 psi. Courtesy of Greg Baehman.

If it's nitro proof and still in proof it matters not whether it is Damascus or modern steel. It will be safe for the cartridges it is proofed for. The one that Drew pictures above is o.k. with any modern 2 3/4" non-magnum cartridge (other than steel shot) that conforms to the CIP standard; that is most European ammunition.

Nice example by the way. There were a lot of good guns that came out of Liverpool. I have a Sumners single 10 bore. Lagopus.....

Good catch 2-piper they'd be battleship armament for sure at those dimensions! Posted before the coffee kicked in!! Forgot the zero's. I usually choose a 1 oz. load between 1150 to 1200 fps and in the 6 to 7 thousand psi range to be easy on the barrels and the wood.

I did a Google search and was able to find this William Sumners hammer gun example (sold in 2006) with serial number 1272 (mine is 2755). Both have the same address on the rib - 48 Old Hall. BillK
http://www.collectorebooks.com/gregg01/shotgun2/Lot-1402.htm

Drew--I think you slipped up on your conversions of bar pressure readings to psi. 740 bar is the transducer equivalent of the crusher-measured service pressure of 650 bar, so you're OK there. But that 850 bar mark is proof pressure also as measured by the crusher method; therefore, needs to be converted to the transducer equivalent. And that is 960 bar transducer, or 13,920 psi.

I'd also note that there are plenty of examples of British guns that have been reproofed--as is quite clear from 2 or more sets of proofmarks--without the crown over R reproof mark. I'd say there are probably more guns that have been reproofed without being stamped with the crown over R than with it.

I was trying to give the non-deep thinkin' Baptist version Bro. Larry. Here's the long version, directly from CIP

The Commission Internationale Permanente pour l'Epreuve des Armes � Feu Portatives standards were not ratified until 1969. Great Britain adopted the 1969 Commission standards March 1, 1980.

http://www.cip-bobp.org/homologation/en/tdcc_public?page=1&cartridge_type_id=7

12g 65mm and 70mm �standard proof� lead or steel (limited to no larger than 3.25 mm and max. fps 1,300).
Numbers are transducer BAR converted to PSI.
SERVICE pressure 740 BAR = 10,733 psi
Maximum statistical individual pressure 850 BAR = 12,328 psi
PROOF 930 BAR = 13,489 psi

12g 76 mm = 3� LEAD �High performance/superior proof� transducer pressure
Service 1050 BAR = 15,229 psi
Maximum statistical individual pressure 1200 BAR = 17,405 psi
Magnum proof 1320 BAR = 19,145 psi

Both 65 and 70 mm 16g standard is SERVICE 780 BAR or 11,313 psi;
Maximum SERVICE 900 BAR or 13,053 psi;
PROOF 980 BAR or 14,214 psi.

Both 65 and 70 mm 20g standard is SERVICE 830 BAR or 12,038 psi;
Maximum SERVICE 950 BAR or 13,779 psi;
PROOF 1040 BAR or 15,084 psi.

OK. I see where you get that, Drew. However, I'm positive the 850 bar stamp refers to the proof pressure as measured by crushers. So still in need of conversion to transducer equivalent. Appears there's a small difference of a few hundred psi between the proof pressure figure provided by the Birmingham proofhouse and that listed in your CIP reference. (Note that the Brits didn't actually start using the bar proofmarks until 1985, and even then they were optional--the individual submitting the gun for proof could request either the metric or the old tons marks until 1989, when it became metric (bars) only.) But when the Brits were using the bars marks, those figures referred to proof pressure only, never service pressure.

Bill, it is a mistake to try to associate quality with brand. All makers/vendors (with the possible exception of Boss) made/bought-in guns to a price point. Very wealthy folks bought best work guns and the rest bought what they could afford. Any shop could get out a best work gun by use of the most skilled out-workers to fill any gap in in-worker skill. The trick was getting commissions to build best guns. The name on the gun will set Brand Value level. The Original Quality grade of the gun was set at build by the price point of the product. I'd guess your gun at Original Quality grade "A", a notch below best work. Sumner will fetch Brand Value level three, 1/2 the value of a similar OQ grade gun with a BV1 m akers name.

DDA

Thank you Rocketman. That actually benefits me, as I can have and enjoy a gun at grade "A" quality, at a price/cost a lot less of a comparable quality gun carrying a BV1 maker's name. BillK