I have 3 54 caliber PRB rifles and both Lee and Lyman molds I ended up using a .535 ball in al 3 with a 18 thou .ticking patch because thats what grouped in less than 3 inches 2100 yds. the 54 is by far the best for long range because it is the one with the highest BC that has a recoil that allows you to shoot it accurate.