Sporting Life July 6, 1895
2nd column 1/2 way down
http://library.la84.org/SportsLibrar.../SL2515023.pdf
1902 H.H. Kiffe catalog
Winchester 1893 Repeating Shotgun illustrated - "The barrel of this gun has been proved with 9 1/2 drams of powder, and 2 1/2 ounces of shot."
The
Banc D'Epreuves Des Armes a Feu De Liege (Proof House for Firearms of Liege) First Obligatory Proof Load for 12g breech plugged "rough forged tubes" intended for “Double-Barreled Breech-Loading Sporting Guns” was 21 grams = 324 grains = 11.8 Drams powder and 32 grams = 1.12 oz. shot.
1917 E.C. Simmons catalog - "Bored For Nitro Powder"
Pete Dickey, “The Winchester Model 97” Feb. 1985
American Rifleman
Damascus barrels were regularly offered up until 1914 [but] cannot be considered “Smokeless Powder” guns.
The "rolled blued steel" was Winchester Standard Ordnance cold rolled Bessemer with a tensile strength about 60,000