If your groups are dead on at several distances, then the point of the arrow is probably staying in-line with your aiming point,and it's the back end of the arrow that's doing the dance. Almost certainly a clearance prob, and it will affect broadhead flight and penetration in game. If your groups are off-center at different distances, then the main prob is simply tuning a bit more precisely.

A simple fix for a clearance probmay be to rotate your nocks so they index differently in relation tothe fletch. Helical fletch and skinny shafts are notoriously tough to clear unless you use a drop away or a bisquit that exerts the same resistance on all the fletchings. I'd mess with just one arrow until you get it good, then copy the nock orientation to the other arrows, and then test each for performance and tweak as needed.

If you can't get the helicals to clear, go to smaller (lower profile) fletch, switch to feathers which are very forgiving, change to offset fletch orientation or a less severe helical, change to a different type of rest, or get fatter arrows.

I wanted the stabillity of helical fletch but had clearance issues, so I went to 4" instead of 5", stuck to fatter shafts (2314's), and then played with the nocks. I feel that keeping the helical was worth the extra changes because hunting ismy main activity with my bow. Everything else is practice, and keeping that blade stable in the air is second only to shooting it in the proper direction in the first place.

Good luck.
-Bulz