Good counsel here on 296. I've used it quite a bit, but increasingly dislike it. The two powders I'd recommend for the .41 are Unique (which is fine loaded down) and 2400.

I much prefer a stout load of 2400, std primers, w/ either jacketed or hard cast 210/215 gr bullets. I have three M57s, have loaded for this cartridge over 25 years, and say with some authority that this is definitely the best for me. As others have said, 296 is a little touchy, requires magnum primers and a really tough crimp. I find it recoils more (apparently) than 2400; I can't explain it technically, but it sure feels that way.