Jesse's last post is good info, one of the important things to figure out is the first place your bullet crosses your poa, somewhere around 10-25yds depending on what zero you go with. This is important because of the large sight offset we deal with on AR based guns. after that shooting on paper every 25 yds out to 100 is good and then every fifty yds beyond 100 is fine.
the offset causes us to aim higher for good impacts on target at close range, especially for clays or head boxes inside 30yds, knowing where to aim high or aim low is important even at close range.
Trapr