Tuning for 3 under

[DDyer]

After shooting split finger for many years I switched to 3 under about a year ago. I was shooting a 66'' longbow that I know was not tillered for 3 under but I had as good or better arrow flight,same thing with a 58'' Grizzly that I have been shooting lately.I just bought a 62'' longbow, I don't know if this bow is tillered for split or 3 under,BUT shooting 3 under the arrows porpoised terribly,I tried moving the nocking point up and down. I got a little better flight after moving the nocking point way up ( almost 1''above 90 degrees),then they didn't group well.I moved the nocking point down and shot split finger and the arrows flew perfectly and I started shooting tight groups,although high.
My Question is, can I do anything as far as tuning to make this bow shoot 3 under,could I take it to a bowyer and have it re-tillered?
I really like the bow and I also like shooting 3 under,I feel more comfortable and I shoot better this way

[vermonster13]

The difference in tiller from split to 3 under is very minor. Sounds like something else is the problem.

[Al Dean]

Try putting a nock under the arrow to keep it from sliding down string.  Also on my bow tillered for 3 under nock height is 3/8".  On my bow not tillered for 3 under nock height is 5/8".