J542 Smith & Wesson Used J Frame Model 642 .38 Special MIM Cylinder Stop & Sprin military surplus A worn or weakened mainspring

A worn or weakened mainspring causes light primer strikes

125" barrel is chambered for

125 inches (4-1/8")

This is a complete trigger assembly

Professional gunsmith installation is required for this part

J542 Smith & Wesson Used J Frame Model 642 .38 Special MIM Cylinder Stop & Sprin military surplus A worn or weakened mainspringJ542 Smith & Wesson Used J Frame Model 642 . 38 Special MIM Cylinder Stop & Spring How to determine the model number of your Smith & Wesson Revolver. Swing out the cylinder , check behind the yoke on the frame for a MODEL NUMBER. Model numbers began in 1957 58. So if there is no model number then your revolver may be older than 1957 58. In this case we can possibly still find the part you need with the serial # . If this is the case contact us and we