If an ATA trap gun is set up by rib configuration and stock dimension to throw the shot charge center 18 inches high to compensate for the rising bird, a dropping ZZ or International Trap bird would have to be lead on the low side by about three feet in addition to lateral lead. This is not a comfortable situation for consistent shooting. I would prefer a gun that throws its pattern dead center to point of aim for ZZ, International Trap, or flyers. However, I believe shooters with much more experience than I sometimes prefer high shooting guns for flyers. I don't know what the majority of experienced shooters prefer. For me, "livelier stock dimensions" means a shorter stock than used in ATA competition and comb drop that allows the eye to line up close to the rib rather than high above it.