Centerfire........guess what? If you are shooting without sights and EVERY shot is going high and left for you?........your doing something CONSISTANT, and consistant is good!

Many of us learned without sights, and know some darn fine compound shooters who shoot instinctively......that has never left me as I learned that way and can honestly strip off my sights and be doing pretty well within minutes.
I learned alot about the basics of archery without sights that carried over into the days when I started competing etc.

Get up close and figure out where you need to hold and aim and think about each shot and trying to do things the same each time and you'll start to see those arrows heading for the center.