I tried the standard 10-20 thousandths off, then I followed whatever the manufacturer recommended. As for bullets and powder, Staball 6.5, H4350, IMR4451. Nosier AB150gr, 168gr ABLR, Barnes 168gr tsx. All of these have shot half way decent. Nobler e-tips 180 gr, Hornady 168gr ELD and 165 gr CX...