I would first number my hunting arrows so you can see which ones don't shoot the same. If they are quality arrows to start with, I would spin test them with the BH's screwed in. Could also compare how a certain arrow shoots with field points as compared to BH's. Try to sort out if the reason the arrow doesn't shoot the same is the head or the arrow itself.

Overall, though, I use the same arrows for practice as for hunting. Helps in getting the pin spacing set. And I would rather have 6 quality arrows than a whole locker full of Wal Mart specials. Don't skimp on arrow quality.