Challenge targets have concentric scoring rings calibrated to your caliber and distance. Each ring is labeled with a group size in MOA or MIL. Find the smallest ring containing all your shots — that ring's value is your extreme spread (center-to-center). Ring diameters include bullet-diameter correction, so no correction math is needed.
Challenge targets are used for quick benchmarking, NRL22 and PRS practice formats, and tracking precision over time. 37 calibers, any distance. Free PDF download.