vane postion

[bowriver]

Hi all, before i start this is not a post complaining about service or products etc just a question. The last batch of arrows i recieved had the vanes set about a 1/2" behind the first batch from the same supplier. Everything else is the same. My f.o.c has not changed noticbly, but i thought this may have an effect on arrow flight. If so what does it effect and how much? Enough to make a difference?

Cheers Paul