feather problem?
 

Ok here is the thing, i put 3 inch feathers on my arrows. I also stuck a new whisker for my biscuit on my bow. well when i went to shot the bow was way off. well i sighted it in. But it is not getting good groups and i can shot the arrow 2 times and one time will shot ok the way of. I was using 4 inch plastic vanes. Now does anyone no what might be wrong? I mean where they fletched wrong or somthing. I also turned the nock and it made it go on more and when i did not turn it, it was shotting way off.