S&W K Frame Model K38 Pre-Model 15 Main Spring .38 Special – Part# 15141

Smith & Wesson K Frame Model K38 Pre-Model 15 Main Spring – Old Style

Restore reliable hammer fall and trigger pull on your K38 or Pre-Model 15 with this factory-original main spring (mainspring). The main spring powers the hammer, providing the force needed to strike the firing pin with sufficient energy to reliably ignite the primer — a weak or broken mainspring causes light strikes, misfires, or complete failure to fire. This old-style blue steel spring is the correct replacement for the K Frame Model K38 (Pre-Model 15) chambered in .38 Special.

• Part Number: 15141
• Fits: Smith & Wesson K Frame Model K38 / Pre-Model 15
• Caliber: .38 Special
• Part Type: Main Spring (Mainspring / Hammer Spring)
• Finish: Blue Steel
• Style: Old Style
• Condition: Used (factory original)
• Installation: Gunsmith fitting recommended

Factory Replacement Quality

Genuine Smith & Wesson factory part manufactured to the exact specifications and tolerances of the original — same spring rate, same dimensions, same reliable hammer energy. No aftermarket substitutes.

Main Spring & Trigger Pull

The main spring is directly related to trigger pull weight — it works in conjunction with the strain screw to set mainspring tension. Replacing a worn spring with a factory-spec part restores the original trigger pull weight and ensures reliable primer ignition. Reduced-power aftermarket springs can lighten the trigger but risk light strikes, especially with hard primers.

About the K38 / Pre-Model 15

The K38 Masterpiece (later designated the Model 15 Combat Masterpiece) is one of the most celebrated K Frame revolvers ever produced. Pre-model revolvers predate the 1957–58 model number system; if your revolver has no model number stamped behind the yoke, contact us with the serial number and we'll confirm compatibility.

Questions? Call or email us — we're happy to help you get the right part the first time.