That's the promise, anyway. Whether it would work in practice remains to be seen. In 2007, California passed a law requiring new makes and models of handguns sold in there to come equipped with microstamp technology, but its effect was delayed until 2013, until the state certified that all gun manufacturers could access the technology unencumbered by patent protections. Some big manufacturers, including Smith & Wesson, have said they won't sell new guns in the state, and several gun rights activists and groups sued to overturn that and other restrictions on the sale of guns there. A federal judge ruled in the state's favor in February on constitutional grounds, though the plaintiffs have signaled plans to appeal. Meanwhile, a state law challenge arguing that the requirement is impossible to comply with is also working its way through the courts. In the meantime, gun manufacturers are selling older models that were grandfathered in to the microstamping requirement. A Washington D.C. law also mandates microstamping for new guns sold in the District, but it doesn't go into effect until next year.