I've been doing the same with slow motion video on doubles. It could always be me but Im squeezing the crap out of the gun with my left and and its not leaving my hand or support hand pointer finger on the trigger guard. Maybe its wrist elbow or shoulder lock but im getting pretty frustrated with it. My groups have been decent but I want it to look good slow motion. Im using a 12lb that came with the gun. Im going to try without and with an 11lb and see if that makes a difference.