Pistol · SAAMI
.40 S&W
Law enforcement favorite in 1990s-2010s.
- Caliber
- 0.4″ · 10.16 mm
- Introduced
- 1990
- Case
- Rimless
- Parent
- 10mm Auto
- Primary use
- Self Defense, Target
- Status
- Active
- Introduced
- 1990
- Type
- Pistol
- Origin
- United States
- Inventor
- Smith & Wesson / FBI
- Manufacturer
- Smith & Wesson
- Standard
- SAAMI
- Status
- Active
- Availability
- Common
- Case capacity
- 19.3 gr H₂O
- Twist (typical)
- 1:16
- Primer
- Small Pistol
- Case type
- Rimless
- Max pressure
- 35,000 psi
- Eff. range
- 50 yd
- Recoil
- 10–15 ft·lb
Introduced by Smith & Wesson
Ballistics
Published velocity/energy data isn't available for .40 S&W. Parent case: 10mm Auto.
Performance
Dimensionscase measurements · scale drawing · size vs familiar rounds
Case dimensions — the scale drawing at the top of the page is built from these.
SAAMI · verified| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 10.16 | 0.400 | ✓ |
| Neck ⌀ | 10.74 | 0.423 | ✓ |
| Shoulder ⌀ | n/a | ||
| Shoulder angle | n/a | ||
| Base ⌀ | 10.77 | 0.424 | ✓ |
| Rim ⌀ | 10.77 | 0.424 | ✓ |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.40 | 0.055 | ✓ |
| Neck length | n/a | ||
| Case length | 21.59 | 0.850 | ✓ |
| Overall length | 28.83 | 1.135 | ✓ |
Size vs familiar rounds
Drawn at true 1:1 — every case is accurate relative to the others. Absolute size depends on your screen's pixel density, so measuring one against a real ruler may be off. .40 S&W is highlighted below.
Factory loads
Being verified
Advertised FPS, energy, and BC are withheld until loads clear verification.
Suitable powders
40 reloading powders listed for .40 S&W, fastest to slowest. Cross-reference in the finder →
Reloading costestimate cost per round vs factory
Estimate your cost per round and how it compares to factory. Inputs are yours — nothing is stored.
Cost estimate only — not load data. Charge weight is your input; follow published manuals for safe charges.
Firearms chambered in .40 S&W
12 models in the database chamber .40 S&W. Browse all →
Lineage
Connected reference
History
Developed in 1990 as FBI's solution after 1986 Miami shootout. FBI wanted 10mm power but agents couldn't handle recoil, so S&W shortened case. Dominated LE for 20 years before agencies returned to 9mm.
FAQs
- What twist rate does .40 S&W use?
- .40 S&W typically uses a 1:16 twist rate.
- What bullet diameter is .40 S&W?
- .40 S&W uses a 0.4″ (10.16 mm) diameter bullet.
- Is .40 S&W still in production?
- .40 S&W is active; typical availability is common.
- What is .40 S&W used for?
- .40 S&W is primarily used for self defense, target.
- What is .40 S&W based on?
- .40 S&W is derived from the 10mm Auto case.
- What are the best powders for .40 S&W?
- Reloading powders commonly listed for .40 S&W include Bull's-Eye, Clays, Vihtavuori N320, American Select, among 40 suitable options.
Sources & provenance
Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 341 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →