Talks between the Motion Picture Association and the Hollywood labor unions have failed to produce an agreement on a new law that would address firearm safety on movie sets. The two sides backed competing proposals earlier this year in response to the fatal shooting of cinematographer Halyna Hutchins on the set of “Rust” in New Mexico last October. Both bills would have established a training standard for film armorers — a job that is currently almost entirely unregulated. The union proposal would have been more sweeping, however, establishing the role of a “set safety supervisor” who would have the power to shut down productions.