Many Damascus guns cannot stand modern Smokeless powder pressures.
Cat
There is little that is more satisfying than using a vintage gun. That said, I try to make sure I will have the same number of fingers on my hands after the shot, as before. And just because the last shot didn't cause the barrels to explode, it doesn't mean the next one won't.
Old guns take careful feeding, and that's after you make sure, often with professional help, that the gun is safe to use in the first place. The most important picture is missing, if the OP is looking for advice from readers, and that is of the proof marks under the barrel. That will state what the gun was designed to use as cartridges and what the gun was built to withstand. The HBC gun was British-made, which is useful as it will have decipherable marks. Of course, these were valid when the gun was new, and some 120 years have gone by since. That is a lot of time in which rust can develop under the ribs, inappropriate cartridges be used, and unskilled hands make 'improvements'. Is the gun on-face, and does it lock up securely, or is there a looseness? Do the barrels have any dents or bulges? On the plus side from the pictures presented so far, it does look in good shape and unmolested -- however, someone knowledgeable about vintage doubles should look at it before considering firing it. The proof marks should settle the question of what the chamber size is, and what pressures the gun was built to withstand (unless the gun was 'modified' at some point, then all bets are off). It may well be that the gun was built for 2 1/2" cartridges, and for black powder only. I often hear comments like "I'll try it with target loads", believing these produce less pressure. This is wrong. Target loads can have the same pressures as hunting loads -- the only low-pressure loads are ones built for low pressure, either by manufacturers, or by someone knowledgeable to make their own. There are instances where modern nitro loads can be used in a gun originally built for black powder, in the case where guns were re-submitted for proof-testing and passed proof: such guns will carry new proof marks indicating nitro proof, and an upper limit of the charge size. Unfortunately there has never been any gun proof requirement in Canada, which puts shooters at a disadvantage and can leave your shooting experience to blind luck. Another argument for having a competent double-gun smith look at it before firing it.
Then there is the matter of damascus barrels. These can be, and have been shown to be, just as strong as fluid-steel barrels, in various tests. All gun barrels will have a point at which going beyond it will lead to rupture. Ways to increase pressure include using overly-powerful powders, cartridges too long for the forcing cone, barrel dents, obstructions, etc. Pressure looks for weak points, and welds can be weak points. Damascus barrels are welded strips, usually of twisted mixtures of iron and steel. Rust can eat away at those welds and create weak points. Yes, the barrels might have shiny bores, but you can't see what is happening/has happened under the ribs. If the bores are pitted, as is common in black-powder guns (due to the corrosive nature of the primers, and the powder), the question is, how deep are those pits? If it affects the welds, how can one tell? Once again, a competent double-gun smith can assess the condition of the barrels. One more thing to remember, barrel dents can be removed on fluid-steel barrels, but removing dents on damascus almost certainly creates weak points at those welds. From the age of the gun, the barrels are either steel or machine-forged damascus. Like all guns, HBC-marked guns were made to a price point, to be 'good enough' for their intended use. In this case, to be a low-cost but serviceable gun. No utility gun was ever made to last over 100 years. It will not have been made from the highest-grade materials, fitted to exacting tolerances, or built by the most experienced hands. That is not to say anything derogatory. It is a fine looking gun, and condition appears to be much better than average. The bore size alone might make this a very desirable and unusual example of a HBC gun. But whether it is advisable to use it in the field is another matter altogether. Using it could lead to damage causing a loss in collector value, if that is a concern.
Full disclosure, I regularly use and hunt with damascus-barreled vintage cartridge guns of the 1860s-era. But these have passed nitro re-proof in the UK, I am careful to only use low-pressure shells, and I have no intention of subjecting them to heavy use.
I would recommend the OP look at another thread, for useful advice on assessing old doubles:
https://www.canadiangunnutz.com/for...r-When-Evaluating-Used-Double-Barrel-Shotguns
The OP might want to get his hands on a copy of the book
'Trade Guns of the Hudson Bay Company 1670-1970' by S. James Gooding. His gun was likely made by one of the following makers: Isaac Hollis; Bentley & Playfair; C.O. Bircham; C.G Bonehill (Ltd.); W.J Jeffrey & Co.; Thomas Bland & Sons; JP Clabrough, and later JP Clabrough & Johnstone; or Joseph Bourne & Son. The Imperials were made in great quantities to special order for the Hudson's Bay Company while others were probably taken from the manufacturer's inventory and stamped with a brand name, explaining the variety of types under the Imperial banner.
