Last updated: March 2026
The S&W Model 940-3 is a 9mm J-Frame snub revolver with a 1.875-inch barrel, 5-shot cylinder, DAO trigger, and concealed hammer. Priced at $899 at White’s Arms in Salt Lake City, it’s one of the few revolvers chambered in 9mm — offering moon clip compatibility with standard 9mm ammo and the reliability of a S&W J-Frame in a compact package.
The Rare 9mm Revolver
Most revolvers are chambered in dedicated revolver cartridges — .38 Special, .357 Magnum, .44 Magnum. The S&W Model 940-3 is different: it chambers 9mm Luger, the most popular handgun cartridge in the world. That single feature opens up a world of ammunition compatibility and cost savings that traditional revolver calibers can’t match.
The 940 series was produced by Smith & Wesson with a specific purpose: give J-Frame revolver fans access to the 9mm cartridge. The result is a compact, no-snag concealed carry revolver that accepts moon clips loaded with standard 9mm ammo — the same ammo you might run in a Glock 19 or SIG P365.
Full Specifications
| Specification | Detail |
|---|---|
| Caliber | 9mm Luger |
| Cylinder Capacity | 5 rounds |
| Barrel Length | 1.875 inches |
| Overall Length | ~6.3 inches |
| Weight (unloaded) | ~23 oz (stainless) |
| Frame | J-Frame (S&W small frame) |
| Action | DAO (double-action only) |
| Hammer | Concealed (enclosed hammer) |
| Magazine System | Full-moon clips (included) |
| Sights | Fixed front blade, integral rear notch |
| Finish | Stainless steel |
| MSRP | $899 |
| Made In | USA (Springfield, MA) |
Why 9mm in a Revolver?
This is the question that every Model 940-3 buyer gets asked at the gun counter. The answer comes down to three practical advantages:
- Ammo cost: 9mm is significantly cheaper than .38 Special or .357 Magnum. If you train frequently, this matters.
- Ammo sharing: If you also carry a 9mm semi-auto (like the SIG P365 FUSE Comp), you carry one caliber instead of two.
- Defensive ammo availability: The 9mm has the broadest selection of defensive loads ever available. Federal HST, Speer Gold Dot, Hornady Critical Duty — all available in 9mm at prices and quantities that far exceed .38 Special +P options.
The trade-off is moon clips: 9mm is a rimless cartridge, so the cylinder requires moon clips to headspace and eject properly. This is a learned skill but not a difficult one.
The Concealed Hammer Advantage
The Model 940-3’s enclosed hammer design means no hammer snag during a draw from a pocket or IWB holster. This is a defining feature of J-Frame carry guns designed for deep concealment. The DAO trigger means consistent pull weight on every shot without external cocking — important for defensive use where you may be drawing under stress.
Range Performance
The 940-3’s DAO trigger pull is heavy — typically 10–12 lbs. This is standard for small-frame S&W revolvers and is a deliberate safety design for a pocket carry gun. At the range, it takes practice to shoot accurately. At defensive distances (7–15 yards), it performs well once you’ve built comfort with the trigger.
With 9mm defensive loads through the 1.875-inch barrel, you get lower velocity than a semi-auto’s longer barrel. Velocity affects terminal performance, so choose defensive loads optimized for short barrels — Federal HST Short Barrel, Speer Gold Dot Short Barrel, and Hornady Critical Defense all exist specifically for snubs.
Pros & Cons
| ✅ Pros | ❌ Cons |
|---|---|
| 9mm ammo — cheaper, widely available | 5-round capacity only |
| Concealed hammer — no snag draw | Heavy DAO trigger — requires practice |
| J-Frame — proven, compact, reliable | Moon clips required for 9mm |
| Ammo sharing with 9mm semi-autos | Lower velocity from 1.875″ barrel |
| Stainless steel — corrosion resistant | Premium price for a snub revolver |
| S&W quality, made in USA | Limited aftermarket vs. semi-auto options |
Moon Clips: What You Need to Know
Full-moon clips are thin steel discs that hold 5 rounds of 9mm in the proper spacing for the cylinder. They’re required — you can’t load individual 9mm rounds without them. Full-moon clips make reloading actually faster than a speedloader in some cases, since the five rounds snap in simultaneously. Purchase several moon clips and a moon clip tool for easier loading/unloading.
Who Buys the Model 940-3?
- Shooters who want a 9mm backup to their 9mm semi-auto carry gun
- Revolver enthusiasts who want the broadest possible defensive ammo selection
- Deep concealment carriers who want a pocket revolver without hammer snag
- Collectors who appreciate rare factory-produced 9mm revolvers
Compare to Our Other Handguns
If you’re deciding between a 9mm revolver and a 9mm semi-auto, the SIG P365 FUSE Comp offers 17+1 capacity at the same $949 price point. The 940-3 offers the simplicity and no-snag draw of a J-Frame with 9mm ammo compatibility. Browse our revolver category and full handgun selection.
Frequently Asked Questions
Do I have to use moon clips with the Model 940-3?
Yes. 9mm is a rimless cartridge, and the cylinder requires moon clips to properly headspace and provide a surface for the ejector rod to push against during unloading. Without moon clips, loading and ejecting 9mm is not practical. Multiple moon clips and a loading tool are the standard accessories for 940-3 owners.
What 9mm ammo works best in the 940-3?
For defensive use, choose ammo optimized for short barrels: Federal HST Short Barrel 150gr, Speer Gold Dot Short Barrel 124gr, or Hornady Critical Defense 115gr. These are designed for snub-nose velocity profiles. For practice, standard 115gr or 124gr FMJ is fine.
Is the Model 940-3 still in production?
The 940-3 is a variant in S&W’s catalog; availability can be limited. Check with us at White’s Arms for current stock — this is a specialized revolver that doesn’t sit on every shelf. When we have it, get it.
How does the 940-3 compare to the Model 640?
The Model 640 is chambered in .357 Magnum/.38 Special — a different cartridge. The 940-3 chambers 9mm. The 640 has a larger following and more aftermarket support. The 940-3 is for shooters specifically wanting 9mm in a J-Frame format.