The .58round ball is really all you need. At almost 300 grains it will do the job, and i would be surprised if you recovered the ball from an elk unless you hit some big bones. A friend of mine took a buffaloe with his .58 using a patched round ball and 120 grains of 2f. Shot was taken at around 60 yards quartering towards the shooter. The ball took out the heart and exited just in front of the hip on the left side. The bull went about 50 feet before it dropped. Use the ball with a good load and you will get your elk.