When does a rifle become a machine gun? That is the question asked in the Supreme Court case Garland v. Cargill. When the Bureau of Alcohol, Tobacco, Firearms, and Explosives suddenly decided to redefine bump stocks as machine guns, many Americans simply complied. However, when Michael Cargill surrendered his bump stocks to the ATF, he did so under protest, filing suit to challenge the rule under the Administrative Procedure Act. Those of us who enjoy and exercise our right to keep and bear arms owe Mr. Cargill a debt of gratitude, but the fight is not over. Thanks to Mr. Cargill's determination and persistence, the ATF's bump stock rule has been found to have not been created correctly, meaning we get our bump stocks back. However, it also leaves open the chance for Congress to do what the ATF could not, violate the Second Amendment one more time.