U.S. NAVAL BASE GUAM, Guam, Nov. 7, 2007 – Ann Brown gripped the handle of a .50-caliber machine gun that appeared to be larger than her slight frame. Peering down the sights, she squeezed off a five-round burst in less than a second. Taken aback by the sudden burst, Brown, president of a graphic design company in Colorado, looked up as if shocked and then laughed, almost embarrassed. She said she didn’t realize it would fire that many rounds so fast. Ann L. Brown, president of New Vista Image, Golden, Colo., marshals in an ambulance for an aerial evacuation...