The SB-200 was not only designed for 22 rifle small bore competitors, but also for varmint hunters and plinkers. It will easily hold 100 rounds in the down position for easy access during competition. Space in the centre is available which can hold up to a 3 50 round boxes. Recently retooled and now fits 17 HMR. The amount each box holds depends on if your ammo came in paper or plastic box originally.