If youre getting a fishtailing wobble in your arrow flight something is out of wack. You may want to check Eastons Arrow Chart. If you have no fletch contact, then check to make sure your rest is square with your nocking point. If thats all good then you may want to check your broadheads. You may be shooting too light or too heavy of a head for your setup. For example, switching to a heavier head to improve FOC can make a shaft too soft and change your tune. Note that the above steps apply to shooting mechanical heads too. While they're generally easier to tune than fixed-blade heads, they're still not field points. I hate to say it, but if you're not willing to work a little to get fixed-blade heads to fly like they should and are still going bowhunting, then you're probably better off using a mechanical head. They may not penetrate as well as conventional heads in all situations, but they're more likely to hit where you're aiming if you're not set up properly.