OLYMPIA, Wash. (AP) — A federal judge has affirmed a set of firearms regulations approved by Washington voters in 2018, ruling against a legal challenge raised by gun-right advocates. The Seattle Times reports Initiative 1639 raised the legal purchase age of a semiautomatic rifle to 21 and established enhanced background checks for their purchase. Voters passed the measure with nearly 60% support but gun-rights advocates have vehemently opposed it. U.S. District Court of Western Washington Judge Ronald Leighton in his ruling cited current federal law banning the handgun sales to people under 21. One of the plaintiffs, Bellevue-based Second Amendment Foundation founder Alan Gottlieb, says the group plans to appeal.