I've got a 657 Mtn Gun and a 57 (both 4 inchers) and I get the velocity you're looking for with 10 gr of Unique. It's been my standard load for over 20 years, and it doesn't hurt to shoot, isn't real dirty, and takes javelina (20-70 yards) with 1 shot. I've shot it in a half dozen or so .41's, and has shot well in all of them.