.50 caliber round balls, in front of 75-100 grs black powder is all you need for whitetails...I shot a custom .45 flint for years, with 80 gr fff...with no problems...I built a .54 flint, after running into a bear on our farms...I shoot 80gr of ff...shoots 2 inch groups at 100 yards...ball blows through both lungs or shoulders on broadside shots...have killed about 25 deer with this gun...Have a buddy that kills deer with a .40 cal...60gr fff...only takes lung shots...within 50 yards...it also works...remember...Daniel Boone died in his sleep at 85 yrs old...he never even saw a conical...LOL