Before Donald Trump had even won last year's presidential election, Gun Owners of America, one of the country's most aggressive second amendment champions, saw an opportunity to use the coming budget bill to overturn one of the country's core gun laws. Their target: the National Firearms Act. Passed in 1934 in response to gangster-era crime, the NFA imposed registration and a $200 tax on machine guns, silencers, and short-barreled rifles and shotguns.