[georgehwbush]

both my ar's 10 and 15 are zeroed at 100yds and both will hit low at any shorter range (ANY SHORTER RANGE) so the 100yard mark is the first crossing of the trajectory and line of sight, that's from imperical testing not just calculations.

now it should be noted that the sights are 2.5 and 2.75 inchs above bore respectively. and the speed of projectile matters too.