Thanks for the advice Dave, as well as the rest of you. I sanded down a few of the nocks and went stumpin today. Much improved flight! Looks like I need to put my nock up a bit, had a little up and down action, but no porpoising at all. I sanded the nocks to where they barely grip the string, and will fall off with a gentle tap. Works great. Any suggestions on what grit sandpaper to use? All I had laying around was 220, and it takes awhile!