I've been using RL15, ARComp, 8208XBR and CFE223 giving me the best velocities. also H4895 for the heavier bullets (105gr Berger Hybrid Target & 108 ELD-M). I'm shooting a 22" Aero Precision Lower & Uintah Precision Bolt Action Upper. Also a 12" X-Caliber Barrel in Pistol configureation.