I just can't get the fishtail out. I got a micro adjustable NAP Apache rest and I have adjusted centershot in 1/32 increments back and forth a dozen times or more and I get it to where it hits where the sight is aiming but the fishtail never goes away. I don't care whether the arrow hits where I want or not when the thing is fishtailing so bad I can see the shaft broadside before it hits. A bare shaft is horrible! On a bare shaft it literally flies sideways right before it hits. It looks like a guided missle from an F16 just sidewinding all over the sky. I think my arrows are underspined but it doesn't make sense. I have tried 75 gr 100 gr and 125 gr field points to no avail and my expandable blade broadheads which are used and I know fly like my field tips in other bows fly way left and low. These same arrows are used in my 1997 Martin pulling same draw weight and draw length and they fly straight as an arrow so how can they be underspined? I tried to call and talk to Joel today but he never returned my call.

Specs and bows:
1997 Martin Speed Demon with Z cams 28" draw and 63 lbs draw weight
2012 Silencer Nitrous cams 28" draw and 60 lbs draw weight
Same arrows for both Goldtip 5575 cut to 29" using NAP Twister vanes fletched at a 2-3 degree offset
75,100, 125 gr tips

Could I be underspined due to the faster more modern bow transferring more energy? Both bows have 7" brace heights