With my current setup (44# recurve 28" draw) I have been shooting 2016s (5 inch feather fletching) with 125gr heads which fly straight and true. I decided I would like to try a slightly stiffer and heavier arrow and ordered a set of 2018s (5 inch feather fletching) and used the same 125gr heads. Well, much to my dismay, these arrows fly like #@!&*#!! I went back to the shop that cut the arrows for me and was told that shooting the heavier arrow was the problem. He, of course, couldn't explain why the heavier arrow would cause fishtailing and helical flight, but I tried his suggestion and tried 100gr heads and the arrow flight became even worse. So I guess my question is what would cause these kind of flight problems??