If you had the same arrow and some of them had straight and some had blazer helical vanes, would you have to change your sight pins? Thanks
Hard to say without shooting them to compare. I will say one thing, helical helps stabilize an arrow faster especially with a fixed bladed broadhead on it.
The short answer is yes. In theory, an arrow fletched with a helical will loss velocity at a faster rate down range. So in that case you may need a sight adjustment...,but then again it may not be enough to notice a typical archery ranges. So your best bet is to try it and see if there is any discernible difference.