I figured out that my barrel just needed to be re-leaded after a cleaning. I'm getting good groups at 35 yards with B Discovery 10.5 gr HP pellets, Crosman Ultra Mags 10.5 dome pellets, AA 10.34 pellets, and JSB 13 gr redesigned monster pellets. Here's a 12 shot group at 33 yards with the Discovery HP 10.5 gr pellets. I settled on 12 shots because I was just seeing if I would get a flyer. When I got to 12 I decided that there was no need to keep shooting.