RE: Are there tricks to tuning a single cam bow?
My single cam Hoyt has the same problem. The nock high tear in the paper won't go away even with the arrow nocked 1/4" low, no matter what rest is on it. I put on a drop away, set it to center shot, broadhead tuned it and it shoots tight groups out to 40 yds. so I just left it that way. If your shafts are spiralling you've got more than just a nock high tear problem. You've got both up/down and rt./lft. issues. Check clearance first, then center shot, then bow torque. Most single cams like an arrow a touch above level or a bit of tiller adjustment.
When I went to the BowTech Binary Cams I set the bow at center shot and puched bullet holes through the paper with perfect tight broadhead groups out to 50 yards without tweaking anything. My single cam is now a back-up bow.