I've always wanted to try a .58 or .62 caliber ball shooter for elk. I've only killed two elk with round ball and they were both .54's. In both cases I shot clear through the animals, and recovery was about like I've come to expect from a double lung hit. One cow died within 30 paces and the other within a hundred. Round ball works pretty well in my limited experience but as always your mileage may vary...