Shotgun · SAAMI
12 Gauge
Most popular shotgun gauge worldwide.
- Caliber
- 0.729″ · 18.517 mm
- Introduced
- 1870
- Case
- Rimmed
- Primary use
- Hunting, Self Defense, Target
- Status
- Active
- Introduced
- 1870
- Type
- Shotgun
- Origin
- United Kingdom
- Inventor
- Various
- Manufacturer
- Various
- Standard
- SAAMI
- Status
- Active
- Availability
- Abundant
- Twist (typical)
- N/A (smoothbore)
- Primer
- 209 Shotshell
- Case type
- Rimmed
- Max pressure
- 11,500 psi
- Eff. range
- 50 yd
- Recoil
- 22–35 ft·lb
- Subsonic
- Capable
Ballistics
Published velocity/energy data isn't available for 12 Gauge.
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 · approximate| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 18.52 | 0.729 | ✓ |
| Neck ⌀ | 20.24 | 0.797 | ✓ |
| Shoulder ⌀ | n/a | ||
| Shoulder angle | n/a | ||
| Base ⌀ | 20.55 | 0.809 | ~ |
| Rim ⌀ | 22.50 | 0.886 | ✓ |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.46 | 0.057 | ✓ |
| Neck length | n/a | ||
| Case length | 69.85 | 2.750 | ✓ |
| Overall length | 69.85 | 2.750 | ~ |
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. 12 Gauge is highlighted below.
Factory loads
Being verified
Advertised FPS, energy, and BC are withheld until loads clear verification.
Suitable powders
44 reloading powders listed for 12 Gauge, 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 12 Gauge
12 models in the database chamber 12 Gauge. Browse all →
Connected reference
History
Standardized in 1870s. Named because 12 lead balls of bore diameter equal 1 pound. Became dominant shotgun gauge. Used in both World Wars and every conflict since.
FAQs
- What twist rate does 12 Gauge use?
- 12 Gauge typically uses a N/A (smoothbore) twist rate.
- What bullet diameter is 12 Gauge?
- 12 Gauge uses a 0.729″ (18.517 mm) diameter bullet.
- Is 12 Gauge still in production?
- 12 Gauge is active; typical availability is abundant.
- What is 12 Gauge used for?
- 12 Gauge is primarily used for hunting, self defense, target, military.
- What are the best powders for 12 Gauge?
- Reloading powders commonly listed for 12 Gauge include No. 1, CSB1, BA10, Vectan BA10, among 44 suitable options.
Sources & provenance
Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 1,351 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →