What bullet diameter is .303 Epps?

.303 Epps uses a 0.312″ (7.925 mm) diameter bullet.

Is .303 Epps still in production?

.303 Epps is wildcat; typical availability is handload only.

What is .303 Epps used for?

.303 Epps is primarily used for hunting, target.

What is .303 Epps based on?

.303 Epps is derived from the .303 British case.

Lindcott Armory

Wildcat · Wildcat

.303 Epps

Also known as .303 British Epps · .303 Epps Improved

Canadian improved .303 British wildcat developed by Ellwood Epps..

Caliber: 0.312″ · 7.925 mm
Introduced: 1950
Case: Rimmed
Parent: .303 British
Primary use: Hunting, Target
Status: Wildcat

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Velocity2,560–2,830 fps

Energy2,619–3,200 ft·lb · est.

Identity

Introduced: 1950
Type: Wildcat
Origin: Canada
Inventor: Ellwood Epps
Standard: Wildcat
Status: Wildcat
Availability: Handload Only

Build

Primer: Large Rifle
Case type: Rimmed

Pressure & range

Eff. range: 300 yd

Ballistics

Representative trajectory · velocity only, no drag model · 100 yd zero0–800 yd

Drop Zero

Velocity only, no drag model: no published ballistic coefficient is on file for .303 Epps, 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: .303 British

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 ⌀	7.92	0.312	~
Neck ⌀	8.61	0.339	~
Shoulder ⌀	11.35	0.447	~
Shoulder angle	35°	—	~
Base ⌀	11.56	0.455	~
Rim ⌀	13.72	0.540	~
Belt ⌀	n/a
Rim thickness	1.63	0.064	~
Neck length	7.06	0.278	≈
Case length	54.86	2.160	~
Overall length	78.11	3.075	~

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. .303 Epps 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.

Powder $/lb Charge (gr) Bullet $/ea Primer $/ea Brass reuses Brass $/ea

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

Lineage

Family TreeOpen .303 Epps in the interactive cartridge family tree

Connected reference

FirearmsFirearms in .303 Epps ToolCompare ballistics

History

Ellwood Epps ("the Canadian Ackley"), ~1950 (documented pre-1965); shoulder 16°→35°, reduced body taper.

FAQs

What bullet diameter is .303 Epps?: .303 Epps uses a 0.312″ (7.925 mm) diameter bullet.
Is .303 Epps still in production?: .303 Epps is wildcat; typical availability is handload only.
What is .303 Epps used for?: .303 Epps is primarily used for hunting, target.
What is .303 Epps based on?: .303 Epps is derived from the .303 British case.

Sources & provenance

Reference Gun Digest / Krause (F+W Media) — Cartridges of the World (Frank C. Barnes, ed. W. Todd Woodard) — British/Canadian wildcat section · bullet ⌀, grain weights
Secondary 303british.com — 303 Epps — Notes on Improved Cases · year, bullet ⌀, velocity, grain weights 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 →