What bullet diameter is .425 Express?

.425 Express uses a 0.423″ (10.74 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.

Wildcat · Wildcat

.425 Express

425 Express

Dangerous-game wildcat by Cameron Hopkins and Whit Collins on a shortened .300 Winchester Magnum case, firing a .423" (.404 Jeffery) bullet..

Identity

Introduced: 1987
Type: Wildcat
Origin: United States
Inventor: Cameron Hopkins, Whit Collins
Standard: Wildcat
Status: Wildcat
Availability: Handload Only

Dimensions

Bullet ⌀: 0.423″
Primer: Large Rifle Magnum
Case type: Belted

Ballistics

Published velocity/energy data isn't available for .425 Express. Parent case: .300 Winchester Magnum.

Reloading cost

Estimate your cost per round and how it compares to factory. Inputs are yours — nothing is stored.

Powder $/lbCharge (gr)Bullet $/eaPrimer $/eaBrass reusesBrass $/ea

Cost estimate only — not load data. Charge weight is your input; follow published manuals for safe charges.

Lineage

Immediate parent

.300 Winchester Magnum

Family TreeOpen .425 Express in the interactive cartridge family tree↗

Connected reference

FirearmsFirearms in .425 Express↗

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 0.423″ (10.74 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.

Data & sources. Specs compiled from the Lindcott Armory reference; the trajectory is modeled (point-mass), not measured. Spotted an error? Report it →