need help as soon as possible
here's the situation:
i had my bow tuned in, proper arrows, good broadheads and was driving tacks at 50 yards. now i cannot get an eight inch grouping at 20 yards. i have no idea what happened, and i took my bow to the local bow tech who knows his stuff as good as anybody else, and he couldn't figure out what was wrong either. i shoot a mathews switchback xt at 70# with easton axis arrows (340) and 100-grain G5 striker broadheads.
my problems started when my rest wouldn't lay over consitently, so i changed it out for a Rip-cord rest. paper tuned it and it was dead nuts. then i started noticing that on occasion my arrows would go anywhere they wanted, and not where i wanted them to. when i fire an arrow it leaves the bow straight and then it turns at about 12-15 yards. i have no idea what could cause this.
the other thing is that with field points the arrows fly true and i hit X's every time. as soon as i put a broadhead on the arrows fly any direction and i can see them altering the course. i've tried 7 different types of broadheads, three different arrows, different spine strengths, different draw weights, adjusted my rest and nock point down and up and nothing makes any difference. like i said, field points fly great, but anything else and the arrow literally turns at about 12 yards. the riser doesn't appear to be bent, and if it is it's tweaked so slightly that it isn't noticeable. i'm at a loss.
my tech suggested that i use some Rage mechanical broadheads just to get me through the season and so i'm off to see if i can get them working like i need but i was just wondering if anyone has ever had this type of problem or can think of something else to try to fix it. i appreciate any help.