Pistol · Proprietary
7.5 FK
Ultra-high-velocity bottlenecked pistol cartridge from FK Brno (Czech Republic).
- Caliber
- 0.307″ · 7.8 mm
- Introduced
- 2014
- Case
- Rimless
- Primary use
- Self Defense, Target
- Status
- Active
- Introduced
- 2014
- Type
- Pistol
- Origin
- Czech Republic
- Inventor
- FK Brno Engineering
- Manufacturer
- FK Brno
- Standard
- Proprietary
- Status
- Active
- Availability
- Rare
- Case capacity
- 22.7 gr H₂O
- Twist (typical)
- 1:10.6
- Primer
- Small Pistol
- Case type
- Rimless
- Max pressure
- 50,763 psi, CIP transducer
- Eff. range
- 150 yd
- Max range
- 2800 yd
- Recoil
- 9.7–10.3 ft·lb
Ballistics
Velocity only, no drag model: no published ballistic coefficient is on file for 7.5 FK, so this is the shape gravity alone gives the advertised velocity. Drag would steepen it. The tool below solves real loads through their published G1 or G7 model.
Open in Ballistic Compare- Parent case
- —
Representative trajectory — modeled from a single velocity input (no published BC for this cartridge yet).
Dimensionscase measurements · scale drawing · size vs familiar rounds
Case dimensions — the scale drawing at the top of the page is built from these.
CIP TDCC| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 7.80 | 0.307 | |
| Neck ⌀ | 8.45 | 0.333 | |
| Shoulder ⌀ | 10.75 | 0.423 | |
| Shoulder angle | 30° | — | |
| Base ⌀ | 10.80 | 0.425 | |
| Rim ⌀ | 10.80 | 0.425 | |
| Belt ⌀ | — | — | |
| Rim thickness | 1.40 | 0.055 | |
| Neck length | 4.00 | 0.157 | |
| Case length | 27.00 | 1.063 | |
| Overall length | 35.00 | 1.378 |
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. 7.5 FK is highlighted below.
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.
Connected reference
History
Developed 2009–2014 by FK Brno Engineering to let a pistol engage targets at 75–150 m while retaining more kinetic energy at range than a 9mm makes at the muzzle. It requires its purpose-built platform: the FK BRNO Field Pistol (2015), later the polymer PSD (2020). Among the fastest production handgun cartridges ever made.
FAQs
- What twist rate does 7.5 FK use?
- 7.5 FK typically uses a 1:10.6 twist rate.
- What bullet diameter is 7.5 FK?
- 7.5 FK uses a 0.307″ (7.8 mm) diameter bullet.
- Is 7.5 FK still in production?
- 7.5 FK is active; typical availability is rare.
- What is 7.5 FK used for?
- 7.5 FK is primarily used for self defense, target.
Sources & provenance
Data & sources. Specs compiled from the Lindcott Armory reference; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →
