Rifle · Obsolete / Non-standard
.280 Jeffery
Obscure early British 7 mm sporting cartridge from Jeffery, made by necking down the .333 Jeffery..
- Caliber
- 0.288″ · 7.315 mm
- Introduced
- 1913
- Case
- Rimless
- Parent
- .333 Jeffery
- Primary use
- Hunting
- Status
- Obsolete
- Introduced
- 1913
- Type
- Rifle
- Origin
- United Kingdom
- Manufacturer
- W.J. Jeffery & Co.
- Standard
- Obsolete / Non-standard
- Status
- Obsolete
- Availability
- Collector
- Primer
- Large Rifle
- Case type
- Rimless
- Eff. range
- 400 yd
Ballistics
Velocity only, no drag model: no published ballistic coefficient is on file for .280 Jeffery, 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
- .333 Jeffery
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.
Wikipedia · approximate| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 7.32 | 0.288 | · |
| Neck ⌀ | 8.05 | 0.317 | · |
| Shoulder ⌀ | 12.80 | 0.504 | · |
| Shoulder angle | 23° | — | ~ |
| Base ⌀ | 13.77 | 0.542 | · |
| Rim ⌀ | 13.66 | 0.538 | · |
| Belt ⌀ | n/a | ||
| Rim thickness | — | — | |
| Neck length | 7.18 | 0.283 | ≈ |
| Case length | 63.50 | 2.500 | · |
| Overall length | 87.63 | 3.450 | · |
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. .280 Jeffery 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.
Lineage
Connected reference
History
W.J. Jeffery, 1913; ~140 gr at ~3,000 fps. Genuinely distinct from the .280 Ross (different maker/design).
FAQs
- What bullet diameter is .280 Jeffery?
- .280 Jeffery uses a 0.288″ (7.315 mm) diameter bullet.
- Is .280 Jeffery still in production?
- .280 Jeffery is obsolete; typical availability is collector.
- What is .280 Jeffery used for?
- .280 Jeffery is primarily used for hunting.
- What is .280 Jeffery based on?
- .280 Jeffery is derived from the .333 Jeffery case.
Sources & provenance
- Reference Gun Digest Books (Frank C. Barnes) — Cartridges of the World (.280 Jeffery entry) · bullet ⌀, velocity, grain weights
- Secondary Cartridge Collector (cartridgecollector.net) — 280 Jeffery Rimless Nitro Express (33/280) · 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 →