Is agent00 a troll you are jerking around?
A nitwit asking a silly question in the absence of a copy of CotW?
CotW shows several black powder military cartridges that kind of top out in the 1900 - 2000 ft-lb energy range. To include 11mm Gras, 11mm Murata, 10.15mm Jarman, and 9.5mm Turkish Mauser. Also the heavy bullet load of .577-450. I bet the .42 Enfield was right up there too, but cannot find detailed data on it. The Jarman and Turk were the latest and "most efficient" and offered in repeating rifles.