Jonathan Dean, 12, yanks on the action slide to load the 20-gauge shotgun, then sights down the length of the barrel. "Pull," he calls softly. The 5-2, 104-pound boy barely flinches as the shotgun recoils against his right shoulder. He’s found his mark: The 4-inch clay disc shatters in the darkening sky of the East Valley. Jonathan is smaller and has less experience than many of the 118 boys and girls who attend statesponsored shotgun training at the Red Mountain Trap and Skeet club just north of Mesa. But he’s already thrilled with the experience, and looking forward to a...