LB58121 Smith & Wesson L Frame Model 581 4" Barrel Blue Used .357 Magnum Pinned Front Sight Model 640-2 (

Model 640-2 (

Fits all barrel lengths

One (1) 4-pocket canvas bandolier

Factory Smith & Wesson barrel

LB58121 Smith & Wesson L Frame Model 581 4" Barrel Blue Used .357 Magnum Pinned Front Sight Model 640-2 (LB58121 Smith & Wesson L Frame Model 581 4" Non Pinned Barrel Blue Used . 357 Magnum Please call or email with any questions! 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