Arrow tuning

I do all of my motecs on my gt xt hunters.I think it makes my broad head arrows group better.

I get them close with my muzzy's but i dont get them perfect, Im shooting a 2.1 fusion vane, 3 vanes with slight right hand helical, I think having them off just a bit helps it spin faster but might just be me....

I shoot either 2 or 4 blade broadheads and 3 fletch (feathers mostly) so no by default.

Bob