I'm using Apex GT-20, 3" and Hal's recipe hand loads 3" both shoot great. Running a IC .555 in the 20" barrel and Sumtoy .562, .570 RR in the 26" barrel. Using TSS #8s in both loads. I lead off with that ammo but back up next two rounds with cheaper Win, LB # 6s. I started out using a Carlson .575 which was decent with LB #6. Remember all guns perform different...Foxtrot makes some excellent ammo also.