i have several damascus and twist barreled guns, ive used IMR7625 in all of these guns, no issues at all, great performance, i have 2 grade A remington model 94"s both 2 stripe damascus, also a lefever heavy damascus sidelock 12 gauge with 3 strip damascus , and a small english sxs hammer gun, twist barreled, im loading in federal hulls 25.5gr of 7625, WIN AA12 wad, 1 1/8oz loads, with WIN 209 primers, load is about 7000psi, works fine, i use winchester target hulls also with 23.5gr same components, only diff is the hull, pressure runs at about 6300 psi, both loads work fine, i use#6, #4 , also heavier shot sizes, BB doesnt offer a high pellet count but it patterns well

hope it helps,