you said lost three deer.did you hit and wound and lose , or did they jump the string and you miss?

anyway, I would say move you pile to 20 yards.also pratice from a tree at the same height.pratice with broadheads on, some time this is a problem with planeing??

I shoot a Barnett quad 400 (now) with spitfire 100 gr. mechanical broadheads and have taken a bunch with it; 4 last year.never had on move till the arrow was sticking in the dirt on the other side.I hold my shots to 30 yards or less amd wait for a good broadside shot.

hope you get it worked out.pratice ; pratice ; pratice the way you hunt all things exact is the main thing.