I just bought my first bow (Martin Exile) on Saturday. I am using a 60 lb draw weight and 29.5 inch draw. It's a great bow and all but I have one problem. When I'm practicing shooting, I can shoot perfect groups all the way out to 25 yards.

However, when I get to 30 yards I am not consistent with my shots. One will be high and the next will be far right. Is this because I am doing something wrong? Or is it something with my sight?