A little more input; According to an article by E H Harrison of the American Rifleman many years back while both Schultz (a bulk smokeless) & Ballistite (a dense smokeless) had been popular in both Europe & England for a number of years Smokeless powder shotshells were not factory loaded in the US until about 1893. BP had also been most commonly used for handloading. Many guns built prior to this designed almost in their entirity for use with black are lighter in their breeches with thinner walls over their chambers than later models. While I am aware that "Pressure is Pressure" I am also aware that black powder is less sensitive & more forgiving of slight errors than is smokeless. For this cause, & realizing some may disagree, if the min bbl thickness over chamber is not at least .090" I personally restrict that gun to the use of black powder. In this same series of articles the invention of the "Pressure Gauge" (crusher) was credited to Thomas J Rodman Ordnance, U S Army, but date not given. He was also credited in 1860 as a Major (later General)of developing a means of controlling the burn rate of black powder for use in large guns by compressing it into a more solid mass to slow it's combustion. The compression was said to limit burning much more than mere granulation size, which had "Only Limited" effect. I suspect the pressure gun was in use well prior to 1900.
