There are very, very few patentable ideas in firearms design After a few hundred years, there are not many truly new ideas left, and the "Accutrigger" is not one of them. There have been many, many "safety triggers" and "automatic safeties "through the decades. Furthermore, a patent is not necessarily worth a whole lot. Especially with a simple mechanism like a trigger, it is awfully easy to avoid patent infringements by making very minor changes in the design without changing the basic function one whit.