Duty/Carry Spring Kit for J-Frame Revolvers

This spring kit is a direct drop-in replacement set for Smith & Wesson J-Frame revolvers. It reduces trigger pull weight by approximately 3 lbs. while maintaining factory safety values. The kit uses a precisely calibrated mainspring and rebound spring to lighten the double-action stroke without compromising ignition reliability. Designed for shooters who want a smoother, lighter trigger pull on carry revolvers without sending the gun to a smith.

Compatibility

• Smith & Wesson J-Frame revolvers (all current production models)
• Model 340PD, 340 M&P, 342, 351PD, 360, 360PD, 361, 362, 432PD, 442, 442 Pro Series, 637, 638, 640, 640 Pro Series, 642, 642 Pro Series, 649, 686 (J-Frame variants), Bodyguard 38, M&P Bodyguard 38
• Not compatible with K-Frame, L-Frame, N-Frame, or X-Frame S&W revolvers

Key Features

• Drop-in installation – no fitting or stoning required
• Reduces double-action trigger pull weight by ~3 lbs.
• Maintains factory sear engagement and safety margins
• Includes mainspring and rebound spring
• 100% Made in USA (Phoenix, AZ)

Install Difficulty & Tools

Difficulty: 2 out of 5 – moderate mechanical skill recommended. Requires mainspring removal tool (or slave pin), small punch set, and a bench block. Detailed instructions included. Expect 20–30 minutes for first install.

FAQ

Will this work with a J-Frame that has an internal lock?

Yes. The kit is compatible with all current J-Frame models, including those with the internal lock system. No modification to the lock is required.

Does the kit include a firing pin spring?

No. This kit includes only the mainspring and rebound spring. The firing pin spring is not included and should not need replacement unless damaged.

Will this reduce reliability with light-striker primers?

No. The mainspring is calibrated to provide reliable ignition with standard and defense-grade primers. The reduced pull weight comes from spring tuning, not from cutting coils or weakening the spring.

Shipping: Ships same business day if ordered before 2 PM EST. Warranty: Manufacturer defects are covered for one year from purchase. Springs are wear items; no warranty on performance after 10,000 rounds.