Look at the velocity and energy tables in the Lyman Reloading manual. You will see that you start getting very inefficient adding more powder after a certain load. You just don't get the added energy down range, much less the extra velocity that you get compared to the smaller amounts of BP. A reasonable charge for a .58 will run around 80-100 grains of FFg. More than that and its burning outside the muzzle, and contributing only recoil to your shoulder. The diameter of the ball and its weight have more to do with how deep it will penetrate flesh at distance, than the velocity it leaves the barrel. A healthy shove from a .58 should be expected; a teeth rattling kick should not. Itws God's way of telling you that you are wasting powder, and dreaming about " knock down power " that does not exist. A .58 will kill Elk, deer, obviously, Bear, Caribou, and moose, all day long, provided you place the shot in the vital areas. Concentrate on accuracy and shot placement, and forget trying to make it in to a .460 Weatherby Magnum. 100 yards is 300 feet, and that is a long way to shoot at any animal. If you can't get closer to an animal than that, it should because you are on one ridge and the animal is on another, and not for any other reason. ( ie. you can't fly!) I saw a film of a Elk or caribou hunt by modern riflemen, and while the camera was focusing on the animal for the 250 yd. plus shot, a coyote ran between the camera and the animal, about 50 yds from the animal. You can see the animal turn and watch the coyote, but it was total oblivious to the long range shooters. Every deer I have shot has been inside 50 yds, and one was only 3 steps away when I shot it. You should not feel handicapped using PRB in a .58 for hunting, nor should you think that you have to have a gun that will kill at 150 yds. Your .58 will do that, and then some, but you owe it to you and the animals you hunt to get closer.