I have a hunting buddy who had a similar problem.At thirty yards his arrows,muzzy 125's were darting everywhere.Of course he was shooting 275 FPS with 4" straight fletch....duh.He had been shooting mechanicals for several years with no problems.Something about that muzzy just turned him on I guess,so he tried em.Needless to say he did'nt want to refletch his arrows so he went back.That bow would shoot a bullet hole through paper by the way.I think the arrows were just knuckleballing due to the straight fletch and big broadhead.One little glitch on the release and off they would go.I don't think they fly as good as hunderheads(JMHO) because they are not as streamlined.IMHO if you cant get a thunderhead to fly well,you've got issues.

Billy

WHACKEM N STACKEM