I second the ACS bows link. Focus on where your bare shafts group and not which way the nock is. Like on the black widow video, an underspined arrow will land to the right at the target, a stiff arrow will land to the left of where you're aiming. My arrows are under spined but if you look at bareshaft nock orientation you'd think they were too stiff.
Also, like some of the other guys stated, you should look at 500 spine arrows or put a lot more weight up front. Full length = 32"?
Get a few 300 - 250- 225 - 200 - 175 point weights to experiment with.
Almost most importantly, on your bare shafts make sure your arrow nocks DO NOT CLIP onto the string! Have them barely clip on, so light that an effortless tap from the finger will knock them off. And be careful they don't come off the string when drawing back. Good luck! It's fun and frustrating at the same time.
Also, have a clean repeatable release each time