If one caliber has any true inherent accuracy advantage over the other, I'd credit the .54's heavier ball to better wind bucking abilities to be the possible answer. A lot depends on what you intend to use any gun for. Neither caliber is of much value for small game, though small game has indeed been taken with both if a solid, accurate load is developed. The larger, heavier ball will do more tissue damage to game and deliver more energy to a metal target...sounds like your decision is aimed in the right direction. Just remember to have fun! :thumbsup: