RE: 58 cal Hawken ?
Gen. Ashley had a Hawken that fired a " one-ounce ball" . I hear that it was close to 66 caliber or so.... 16 balls to the pound.
" It seems very difficult to impress most reloaders with the fact that every rifle is an individual, and what proves to be a maximum load in one may be quite mild in another, and vice versa." Bob Hagel, GAME LOADS AND PRACTICAL BALLISTICS FOR THE AMERICAN HUNTER, 1977