hi, ive got a .22 11.5 ftp rifle, i was thinking is there a formula for working out pellet trajectory, e.g. a scope has 2 zeros, 1 at 10 yards and 1 at 30 yards were if you zero your scope to 10 yards it will be aiming dead on at 30 yards, i dont know if this is true i read it somewere and crnt redmember were