Shares of gun and ammo makers were trading mixed midday Thursday, after New York’s attorney general sued the National Rifle Association, seeking to put the gun advocacy organization out of business over allegations that high-ranking executives diverted millions of dollars for lavish personal trips, no-show contracts for associates and other questionable expenditures. Shares of Sturm, Ruger & Co. Inc. were up 0.4%, little changed after the announcement; while Smith & Wesson Brands Inc.’s stock was off 1.4%%, slightly lower. Meanwhile, ammunition and outdoor products maker Vista Outdoor Inc.’s shares were trading 16.5% higher on the session, at last check. Attorney General Letitia James’ lawsuit, filed in state court in Manhattan after an 18-month investigation. Market Pulse Stories are Rapid-fire, short news bursts on stocks and markets as they move. Visit MarketWatch.com for more information on this news.