I tried a 15 yd zero for my RMR for my first several matches in CO, and then moved to a 25 yd zero thereafter. It has worked much better as there apparently were some deficiencies that showed up at the longer distance. The 15 yd zero on a 25 yd target was several inches off. My 25 yd zero on a 15 yd target is exactly dead on. At 10 yds several aimed shots result in one ragged hole in a 1" paster. That might make a difference on a tight shot during a match.