i am shooting a martin threshold
63lbs
29" draw
with carbon express mutiny 350's
with a 125g montec g5 broadhead
i am having trouble (to me) it looks like they arrows are fishtailing they are hitting in decent groups.
i checked the rest - no contact had the pro shop look at it and they said it was all in tune.

could i be over/under spine ?
any help would be great thank you