These custom EDM matched parts (Electrical Discharge Machining; a process that allows manufactures to limit variance to +/-.0001") are surface ground together for ultimate surface smoothness. That special treatment reduces inconsistency and creep and gives a pull weight in the range of 2-1/4 to 2-1/2 lbs. Includes match hammer and sear. Does not fit Ruger 10/22 Magnum.
Some Ruger 10/22 models will require the use of two Ruger hammer bushings for proper installation (product 510559). 10/22's that already have separate hammer bushings will not need new ones as the factory ones can be re-used.