Re velocity, I pulled out an old (1990) copy of The Complete Black Powder Handbook by Sam Fadala, and he says on pg 192:
"My 12 gauge mentioned above loaded with 1-1/2 ounces of shot and 100 grains volume of FFg blackpowder or RS Pyrodex gains a muzzle velocity of close to 1200 fps." Later in that paragraph he says that dropping the shot charge to 1-1/4 oz adds about 100 fps to velocity. Sounds just like a modern nitro load of 1-1/4 oz. He used an Oehler Model 35P proof chronograph, as described on page 50.
