I hold mine down, not classy to see your fine firearm bouncing off the concrete bench (does happen when the hands arn't working). I think? I see about .5-1 min or so differance on chickens from bench to position and that being shots going lower. (holding it down?) checking from position is the best but unless you've a considerable good hold and call radius and mighty big dose of confidence you could smoke a barrel and have the match starting and still not be set up yet. Sight in with enough shots to see a group with elevation and windage in mind at then current conditions. Unless you're blessed with one of those ranges that has fairly stable conditions you're likely out west to see everything change several times during the course of a match. Afternoons in Phoenix it was several times each bank of turkeys.
Good Luck,
Carroll
PS HighPower tests all your frailties, and makes them public!!