Last updated: March 2026
The best S&W Model 940-3 upgrades include tritium night sights, an aftermarket J-Frame grip, a moon clip loader tool, and a quality pocket or IWB holster. Since the 940-3 is a reliable, simple revolver, upgrades focus on carry comfort, low-light performance, and reloading speed rather than performance modifications.
Upgrading a Simple, Reliable Platform
The S&W Model 940-3 doesn’t need much. It’s a revolver — simple, reliable, with minimal moving parts. Unlike semi-autos where trigger kits, slides, and barrels are common upgrades, a revolver’s upgrade path is mostly about making the gun more comfortable to carry and use. Here’s what experienced 940-3 owners add.
Top S&W 940-3 Upgrades & Accessories
1. Tritium Night Sights — Highest Priority
The 940-3’s factory fixed sights are standard black on black — fine in daylight, difficult in low light. Adding tritium night sights is the single most impactful upgrade for a carry revolver. XS Sights makes a tritium front bead for J-Frame revolvers that is bright, durable, and widely considered the standard upgrade for snub-nose defensive use.
- XS Sights 24/7 Standard Dot (~$60–$80): Best for fast acquisition in low light
- XS Big Dot Tritium (~$70–$90): Larger dot for faster target acquisition under stress
- Professional installation recommended unless you’re experienced with gunsmithing
2. Aftermarket Grips
The standard J-Frame grip on the 940-3 is functional but leaves room for improvement in both concealability and comfort. J-Frame grips are one of the largest aftermarket categories in revolvers:
- Pachmayr Compac Professional (~$25–$35): Rubber grip that significantly improves recoil absorption. Our most-recommended budget grip upgrade.
- Hogue Monogrip (~$25–$40): Finger groove design, comfortable for medium-to-large hands
- VZ Grips Operator II (~$60–$80): G10 material, aggressive texture, excellent for wet conditions
- Crimson Trace LG-405 Laser Grip (~$200–$250): Integrated laser activates on grip — adds defensive advantage in stress situations
3. Moon Clip Loading Tool
Loading moon clips by hand is possible but requires more force than is comfortable for everyday carry prep. A dedicated moon clip loading/unloading tool makes this quick and easy. The Dade Machine Moon Clip Tool (~$20–$30) or similar devices take the friction out of the process. Buy 6–10 moon clips and the tool together — this is a mandatory accessory kit for the 940-3.
4. Speedloaders (as Backup)
While moon clips are standard for the 940-3, some owners also carry a Comp II or HKS speedloader as a backup reload option. HKS makes J-Frame speedloaders that fit the 940-3’s 5-shot 9mm cylinder. Speed strips (Tuff Products) are flatter for deep concealment but slower to use.
5. Action Job (Professional)
A professional gunsmith can perform an action job on the 940-3’s trigger mechanism — polishing the internals and adjusting springs for a smoother, slightly lighter pull. S&W J-Frame action jobs are a common service at any competent revolver gunsmith. Cost: $50–$100. Result: a noticeably smoother trigger pull that aids accuracy in practice.
Important: only use a gunsmith experienced with S&W J-Frames. Incorrect spring work can cause reliability issues.
6. Crimson Trace Laser Sight
The Crimson Trace LG-405 is the most popular J-Frame laser grip — it activates automatically when you grip the gun normally, projecting a visible red dot on target. For defensive use, this is valuable: in high-stress situations, many shooters focus on the target rather than the sights. A laser helps maintain accurate fire without a perfect sight picture.
7. Carry Accessories
A quality moon clip holder for spare rounds on the belt or in a pocket is practical. Tuff Products QuickStrips and dedicated moon clip pouches from various leather makers keep reloads accessible for carry use.
Upgrade Priority Table
| Upgrade | Priority | Cost | Impact |
|---|---|---|---|
| Tritium night sights | 🔴 High | $60–$90 | Critical for low-light defense |
| Moon clip tools + extra clips | 🔴 High | $25–$50 | Essential for practical use |
| Aftermarket grips | 🟡 Medium | $25–$80 | Comfort and recoil management |
| Crimson Trace laser | 🟡 Medium | $200–$250 | Low-light defensive advantage |
| Action job | 🟢 Nice to have | $50–$100 | Smoother trigger for training |
| Holster | 🔴 High | $25–$100 | Safe carry — non-negotiable |
What You Don’t Need to Upgrade
The 940-3’s barrel and cylinder are matched to the gun — don’t attempt to change them. The DAO trigger mechanism is precisely set; spring kit installations should only be done by qualified gunsmiths. The stainless finish is durable as-is; no additional coating or finish work is needed.
Related Carry Options
If you’re building out a 9mm carry ecosystem, the 940-3 pairs well with a 9mm semi-auto primary like the SIG P365 FUSE Comp. Browse our revolver selection and full handgun inventory at White’s Arms.
Frequently Asked Questions
Can I dry-fire the S&W 940-3 for trigger practice?
Yes — S&W J-Frame revolvers are generally safe to dry-fire. However, snap caps (dummy rounds) are recommended to protect the firing pin during dry-fire practice. Pachmayr and A-ZOOM make 9mm snap caps that work in the 940-3’s cylinder with moon clips.
How many moon clips should I buy?
We recommend 8–10 moon clips minimum for the 940-3. Use 2–3 for daily carry reloads, 5–7 for range sessions. Moon clips are inexpensive ($2–$5 each) and having plenty makes range practice smooth.
Is the Crimson Trace laser worth it for a carry revolver?
For defensive use, yes. The grip-activated design means no additional manipulation — grip the gun normally and the laser is on. Many defensive shooting instructors recommend laser-equipped J-Frames for shooters who may be in low-light environments or who have difficulty with precise sight alignment under stress.
Does an action job affect the 940-3’s reliability?
When performed correctly by an experienced gunsmith, an action job improves feel without affecting reliability. Incorrect spring work that reduces pull weight too much can cause light primer strikes. Always use a gunsmith who specializes in S&W revolvers and request that they maintain factory reliability standards.