The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) tried this year to impose a regulatory ban on a very common AR-15 rifle ammo: M855, known as "green tip." The agency claimed it was merely ending a previous exception to a general ban on "armor piercing" ammunition. The green tip bullets were previously allowed on the grounds that they have a legitimate "sporting purpose," but the ATF claimed a new class of handguns could accept the ammo as well; since such ammo in handguns has been prohibited since 1986, it concluded, the M855 should be banned.
Yet ATF's own statutory definition of "armor piercing" excludes the M855, since its core is lead. The statute defines the banned category as made "from one or a combination of tungsten alloys, steel, iron, brass, bronze, beryllium copper, or depleted uranium."
After receiving over 80,000 public comments, and objections from a majority of the Senate, the ATF backed down. A March press release insisted that the agency was trying to make a "good faith interpretation of the law [that] balanced the interests of law enforcement, industry, and sportsmen," but explained that the negative comments convinced them to do "further study." Rep. Eliot Engel (D–N.Y.) then introduced a bill to impose the M855 ban by law—not the sort of legislation that has had much political luck lately.