per Eley Brothers 1910 table it sent a 270 grain bullet downrange at 1975 fps from 40 grains of cordite for 2336 ft lbs of muzzle energy , assuming a 28 inch barrel. Loads for it in first and second editions of Graeme Wrights 'Shooting the double rifle". I don't have the latest edition so can't say what he has in there. PM me if you want them.