doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Nitro Proof Damascus 2-1/2 inch

I have a Westley Richards Gold Name with nitro proofed Damascus barrels. The bore dimensions are marked 12 over1 and the bores both measure .739. Am I correct that 12 over 1 is .729 + .010 for a total of .739? The bore are bright and shiny. Is there any reason I should not use RST, Gamebore and B&P 2.5 inch ammo in the gun? How about Winchester 2-3/4" extra light?

12 by itself is .729. If it is opened more than .010 it is out of proof. 12 over 1 is .740 out of proof at .750. This according to Shotgun Technicana by McIntosh and Trevallion

Looks like you're good to me proof-wise, but what is the wall thickness?

https://www.vintageguns.co.uk/magazine/proof-sizes

I have shot a few rounds of very light factory loads in my 2.5 inch chambered damascus barreled SLE as an experiment. No noted adverse effects, although I wouldn't call myself comfortable with it. Also bores are at .732 as proofed (or near) with .030 MWT.

I have a wall thickness gauge. What is considered minimum for Damascus?

Not sure, but I had a hammergun originally proofed as a 12 bore at .729 that had been hogged out to .783 with 10 gauge chambers. It was fairly high quality laminated steel. MWT was about .90 at the forcing cone and .021 out near the chokes. I thought that was fine with low pressure loads. Someone had obviously put some heavy loads through it at some point because there was evidence of riveling. I think the bigger risk is pitting and/or inclusions, but it sounds like you have a pretty clean gun where that is less likely to be an issue. My other damascus guns have had MWT's of 030 and 040. None have given me any issues.

Also, there is that late 1890's proof house test where damascus outperformed early steels so it is all relative to some degree. Drew has a lot of info on that, and I am sure will be along shortly.

Under the Supplementary Nitro Proof rules of 1904, 12g 2 1/2” and 2 5/8” chamber guns were proved for service load 1 1/8 oz.
In 1925, the 2 1/2” & 2 5/8” 12g maximum service load was 3 Dr. Eq. with 1 1/8 oz. shot with a mean pressure of 3 1/4 tons by LUP = 9,800 psi by Burrard’s conversion.
Post 1954, the "Highest Mean Service Pressure" for 2 1/2” chamber was 3 tons = 8,938 psi

12 means bore .729 - .739"
12/1 means bore .740-.750" (11 is .751)
13/1 or 12 would be much more common. Is there a Crown over R reproof mark?

Pattern welded barrel strength
https://docs.google.com/document/d/1cvqRzkg0wEjhAAcFWr8gFi7aPFRsSIJ_hahfDxmrNAU/edit

Wall thickness recommendations
https://docs.google.com/document/d/1ZIo0y746UsSRZIgRuuxwAbZjSBHitO_EanvwLYc-kGA/edit

Please let us know the end-of-chamber, 9" and minimum wall thicknesses and location thereof.

be safe...

if you must shoot it, then shoot black...

be safe...

Here is the photo of the proofs. Unfortunately upside down but I didn't want to wait 4000 seconds to repost

https://imgur.com/gallery/WsJWhDu

In viewing the proof marks on the barrel flat photo you supplied, I see the Birmingham viewers mark with the letter "E" on the left of the crossed sceptres indicating that this gun was re-proofed in the year 1954. There are other marks associated with this re-proof such as 2 1/2" and the 12 inside the angle pointed square. The 2 1/2 inch and the 1 1/8 oz marks leads me to believe the gun was reproofed early in 1954.

Yep.



The original proof was likely 1887-1896. 1896-1904 would be marked 1 1/8 oz Max. 1904-1925 1 1/8 oz Shot
Some of the previous proof marks were over-stamped with NITRO PROOF 1 1/8 oz. The large 12 over C in a diamond is from the reproof.
The gun was originally proved at 13/1, was honed (thereby 'spaining the mirror .739" bore) and then reproved at 12/1

The wall thickness numbers are critical regarding choosing the appropriate loads.
ed is well aware that today we can easily reproduce the pressures of the black powder loads actually used when the gun was manufactured.