Wildcat · Wildcat
.425 Express
Dangerous-game wildcat by Cameron Hopkins and Whit Collins on a shortened .300 Winchester Magnum case, firing a .423" (.404 Jeffery) bullet..
- Caliber
- 0.435″ · 11.049 mm
- Introduced
- 1987
- Case
- Belted
- Parent
- .300 Winchester Magnum
- Primary use
- Hunting
- Status
- Wildcat
- Introduced
- 1987
- Type
- Wildcat
- Origin
- United States
- Inventor
- Cameron Hopkins, Whit Collins
- Standard
- Wildcat
- Status
- Wildcat
- Availability
- Handload Only
- Primer
- Large Rifle Magnum
- Case type
- Belted
- Eff. range
- 200 yd
Ballistics
Velocity only, no drag model: no published ballistic coefficient is on file for .425 Express, 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
- .300 Winchester Magnum
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.
SAAMI · approximate| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 11.05 | 0.435 | · |
| Neck ⌀ | 11.58 | 0.456 | · |
| Shoulder ⌀ | 13.72 | 0.540 | · |
| Shoulder angle | — | — | |
| Base ⌀ | 13.79 | 0.543 | · |
| Rim ⌀ | 11.86 | 0.467 | · |
| Belt ⌀ | — | — | |
| Rim thickness | — | — | |
| Neck length | — | — | |
| Case length | 67.06 | 2.640 | · |
| Overall length | 83.82 | 3.300 | · |
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. .425 Express is highlighted below.
Missing a dimension for .425 Express? 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.
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
Connected reference
History
Built 1987 on a Ruger M77; replicates .404 Jeffery ballistics in a standard-length action. Thin/community sourcing.
FAQs
- What bullet diameter is .425 Express?
- .425 Express uses a 0.435″ (11.049 mm) diameter bullet.
- Is .425 Express still in production?
- .425 Express is wildcat; typical availability is handload only.
- What is .425 Express used for?
- .425 Express is primarily used for hunting.
- What is .425 Express based on?
- .425 Express is derived from the .300 Winchester Magnum case.
Sources & provenance
- Manufacturer Quality Cartridge — Quality Cartridge .425 Express Brass (via Graf & Sons) · bullet ⌀
- Reference Gun Digest Books — Cartridges of the World (Frank C. Barnes) · year, velocity, grain weights, bullet ⌀
- Secondary Cartridge Collector (cartridgecollector.net) — .425 Express · year archived
Data & sources. Specs compiled from the Lindcott Armory reference; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →