Everybody seems to load this round using blackpowder, but the commercial companies, including KYNOCH, also loaded it with smokeless, right to the end of production.
A powder which is relatively safe in the old blackpowder rifles is SR 4759 if used in a THIRTY-EIGHT PERCENT mode: take the blackp;owder load and multiplyt it times point thirty-eight and that is your smokeless loaing for SR4759..... a 100-grain blackpowder charge computres to 38 of the smokeless, a 50-grain blackpowder charge computes to 19 grains and so forth.
This is a good old-timey powder for most of the big blackpowder rounds, works fine in the .43 Mauser also. Just for laughs, I have a friend who is also using it in a 300 Weatherby, with 150-grain Hornadys..... they are coming out at about 1700 ft/sec and shooting teenytinylittle groups.
But this old powder does work well in many of the old blackpowder rounds..... ignites perfectly at low loading density, zero residue, it isn't hard on the bore AND it's cheap to shoot. And ya don't gotta do the boiling-water-through-the-barrel trick afterwards, either! Bonus!
