I am trying to help my nephew sight in his new rifle (Marlin 336 30-30 with a 20 inch barrel) and we are having trouble figuring out what distance to zero it in at. The ballistic data for Hornady LeverEvolution Ammo is -1.5 @ Muzzle/+2.9 @ 100 yds/ 0 @ 200 yds. I have zero experience with this cartridge, and the charts I looked up online recommended zeroing in anywhere from 25 yds to 60 yds. Can someone who has experience with this cartridge please let me know what worked best for you?