Drew;
My post on the bored for nitro is primarily based on Lefever catalogs. In their catalog circa 1892 they state under "For Trap or Duck Shooting" for brass shells to use two felt wads over powder two sizes larger than bore of gun, for paper shell same except one size larger than bore.
under "For field Shooting" they state for our new gun built for the use of Nitro Powders use one paste-board wad & three felt wads same size as bore.
in another section of the same catalog they state that their guns made especially for Nitro Powders; "These guns we are boring smaller for the use of wads same size as bore. We find by testing these powders better results are obtained with a slightly smaller bore in order to prevent the escape of gas.
In this catalog the only grade offered with steel barrels was the Optimus with Whitworth Fluid Steel @ a list price of $400.00. Whitworth was also an option listed for the Optimus grade in an 1889 price list, I do not know how much earlier it was available.
Essentially it appears to me the "Bored for Nitro" has nothing to do with the actual metal the barrel was made from, but rather the size of it's bore.
