uneven fletching
I dont have access to a fletching jig, so my (helical) vanes are not glued perfectly in all respects: the vain may not be straight, the vanes may not be spaced evenly around the shaft, and their offset may not be identical.
Dont get me wrong. It's NOT a total mess, but the flaws are big enough to be visible.
How much do you expect such flaws will effect accuracy?