But Frank Stelmach of Double Tap Shooting Range and Gun Shop invited me, videographer Michael Sheridan and reporter Adam Shrier to come down. Stelmach is not like many gun lovers. He admires his weaponry, yes, and has difficulty explaining why law-abiding citizens need a gun that can empty a 40-round magazine in a few seconds. But he also hates the idea that “bad people” get a hold of a gun like this and use it to kill without difficulty. “There should be expanded background checks — extending into your family, friends and associates,” he said. “And there should be a...