The most important calculation will be on the sear which releases the piston.... The critical dimensions are the diameter of the pivot pin, how much material there is around the pin (width and thickness) on the sear and on the trigger box (supporting the pin).... plus the area that is loaded where the sear contacts the piston (on both components).... Those are the parts with the greatest load.... IF those have a sufficient safety margin, then it would pay to do similar calculations on the other intermediate levers and pivot pins.... Bob