I'm only using JSB and Hatsan 81.02 pellets. I'm getting 1.5" five shot groups at 50 yards, and 3.25" at 100. When I started, this gun I was using heavy bullets but found pellets are most accurate. JSB at 830 ft per second were the sweet spot for me. There is not much difference between JSB and Hatsan, expect Hatsan has a few more flyers per can. They are worth the savings if you do quick sort.