Our single stage trigger drops into nearly all 10/22® models with little exception. If this trigger is going in a SR-22® please let us know so that we may remove a small amount of material from the rear tang. With our recently updated look, we have slimmed down the rear of the trigger guard so that it now fits without modification into the pistol grip style stocks that engulf the rear of the trigger guard giving the rifle that handgun appearance around the trigger area.