Pistol · Obsolete / Non-standard
9x25 Dillon
Mike Dillon's competition pistol cartridge created by necking down 10mm Auto to 9mm.
- Caliber
- 0.356″ · 9.042 mm
- Introduced
- 1989
- Case
- Rimless
- Parent
- 10mm Auto
- Primary use
- Self-Defense
- Status
- Discontinued
- Introduced
- 1989
- Type
- Pistol
- Origin
- United States
- Inventor
- Mike Dillon
- Manufacturer
- Dillon Precision
- Standard
- Obsolete / Non-standard
- Status
- Discontinued
- Availability
- Collector
- Case capacity
- 22.8 gr H₂O
- Twist (typical)
- 1:16
- Primer
- Boxer Small Pistol
- Case type
- Rimless
- Max pressure
- 37,500 psi, SAAMI transducer
- Eff. range
- 50 yd
- Max range
- 2600 yd
- Recoil
- 9.4–9.7 ft·lb
- Subsonic
- Capable
Ballistics
Published velocity/energy data isn't available for 9x25 Dillon — an obsolete/collector cartridge. 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 · approximate| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 9.04 | 0.356 | · |
| Neck ⌀ | 9.65 | 0.380 | · |
| Shoulder ⌀ | 10.74 | 0.423 | · |
| Shoulder angle | 30° | — | ~ |
| Base ⌀ | 10.79 | 0.425 | · |
| Rim ⌀ | 10.79 | 0.425 | · |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.40 | 0.055 | · |
| Neck length | 9.33 | 0.367 | |
| Case length | 25.15 | 0.990 | · |
| Overall length | 31.75 | 1.250 | · |
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. 9x25 Dillon is highlighted below.
Missing a dimension for 9x25 Dillon? Some case measurements aren't in a published SAAMI/CIP drawing yet. Have a factory or reamer print? Send it → — verified hard-to-find data earns a free Lindcott sticker.
Factory loads
Being verified
Advertised FPS, energy, and BC are withheld until loads clear verification.
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.
Lineage
History
Developed by champion shooter Mike Dillon in 1989 for IPSC Open Division competition. The cartridge necks down 10mm Auto brass to accept 9mm bullets, producing extraordinary velocities around 1,600 fps. Creates major power factor in Open pistols using minimal compensator-friendly case volume. Never commercially produced; hand-formed brass only.
FAQs
- What twist rate does 9x25 Dillon use?
- 9x25 Dillon typically uses a 1:16 twist rate.
- What bullet diameter is 9x25 Dillon?
- 9x25 Dillon uses a 0.356″ (9.042 mm) diameter bullet.
- Is 9x25 Dillon still in production?
- 9x25 Dillon is discontinued; typical availability is collector.
- What is 9x25 Dillon used for?
- 9x25 Dillon is primarily used for self-defense.
- What is 9x25 Dillon based on?
- 9x25 Dillon is derived from the 10mm Auto case.
Sources & provenance
- Standard SAAMI — SAAMI cartridge & chamber drawing — 9x25 Dillon archived
- Standard SAAMI — ANSI/SAAMI Z299 — Cartridge & Chamber Drawings archived
- Secondary Cap & Ball — 9x25mm Dillon dead-calibers profile · parent_cartridge
- Secondary 9×25mm Dillon — Wikipedia (cites Lyman Pistol & Revolver Handbook 2nd ed. p.91; Marshall & Sanow) · parent_cartridge
Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 18 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →
