Floxter:

Your diagnosis could be correct if a paper tune or bare shaft shows that shaft impacted tail high ,which would indicate that the string nock may have to be lowered. I say "could" and "may" because we know that nothing is certain in archery until an adjustment of gear or form actually corrects the problem.

I am responding first to the statement that he can see that the nock-end of his shaft is already "nock high" at 10 yards out, indicating that the shaft may be slightly porpoising. That could indicate that the nock end is being pushed down by a too low nock point and is causing hard contact with the fletch and the bow shelf. Since he said he had already moved his nock up, I opted for the too low and contact diagnosis.

I also suggest that he check for shaft nock tightness to string.

As for the release affecting the natural tiller of the bow; maybe. I shoot 3 fingers under on bows not tillered for 3 under and have never noticed a critical difference. However, I am with you on having a critical eye upon that release. My experience with testing a caliper release on a recurve, was that I had to forcibly pull the trigger to get it to release, and the release of the string was loud and harsh. In addition, with the release, the caliper end is probably applying some heavy pressure against the nock, which we know will cause bad arrow flight.

I presently still opt for 1) the string nock being too low, but will go with trying a higher set to at least ½" above 90 degree and, 2) that he may need to get his shaft above the shelf regardless of correct nock set.

One problem though; the release may be the culprit for this problem.

I need the bow and shooter specs. I always feel like I am stabbing in the dark trying to suggest possible causes and solutions without knowing the specs and present setup.