Gun manufacturer Smith & Wesson Corp. says it won't sell new models of its semi-automatic handguns in California to avoid complying with a provision in the state's gun law that took effect last year. Springfield based Smith & Wesson said it won't add microstamping, a marking used to differentiate bullet casings, on those products as the law requires. The company said microstamping is cost prohibitive and unreliable as a crime deterrent. Smith & Wesson said it expects sales of its California-compliant revolvers, which aren't required to have microstamping, will offset the impact to the company. Smith & Wesson said the California law, which also requires re-approval of pistols that undergo enhancements or improvements other than cosmetic changes, challenges all manufacturers. Two gun industry trade groups are challenging the microstamping requirement in California state court.