Ok guys, got kinda a odd deal here. First off, I'm shooting a Bowtech Guardian, 29" draw, 67 pounds and Easton FMJ's (267 fps). I have a HHA Optimizer or whatever, pendulum sight. It has those stupid stickers that you put on with the preset ranges. I thought I had the right one but....now I have a problem. I am DEAD on at 20, 25, 30, and 35 yards. I mean like right on, no doubt about it. But, when I go to shoot at 40 I am like 8 inches low!! How can this be with a difference of just 5 yards? Could it be because I'm shooting such a heavy arrow? Any help appreciated!