Rifle · Military
.303/25 Cadet
Cadet training cartridge formed by necking the .303 British to .25 caliber; used in Australian and British cadet rifles to reduce cost and recoil while maintaining .303 brass..
- Caliber
- 0.257″ · 6.528 mm
- Introduced
- 1906
- Case
- Rimmed
- Parent
- .303 British
- Status
- Discontinued
- Introduced
- 1906
- Type
- Rifle
- Origin
- Australia
- Inventor
- Australian Army
- Standard
- Military
- Status
- Discontinued
- Availability
- Rare
- Primer
- Boxer Small Rifle
- Case type
- Rimmed
- Max pressure
- 38,000 psi
- Eff. range
- 250 yd
Ballistics
Velocity only, no drag model: no published ballistic coefficient is on file for .303/25 Cadet, 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.
Wikipedia · approximate| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 6.53 | 0.257 | · |
| Neck ⌀ | 7.37 | 0.290 | ~ |
| Shoulder ⌀ | 10.19 | 0.401 | ~ |
| Shoulder angle | 20° | — | ~ |
| Base ⌀ | 11.68 | 0.460 | · |
| Rim ⌀ | 13.72 | 0.540 | · |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.52 | 0.060 | ~ |
| Neck length | 6.35 | 0.250 | ≈ |
| Case length | 56.44 | 2.222 | · |
| Overall length | 72.39 | 2.850 | ~ |
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. .303/25 Cadet 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
Developed for Australian and British cadet rifle training in the early 1900s, the .303/25 allowed cadets to train with shorter single-shot rifles using full-length .303 cases reformed to .25 caliber. The lower powder charge reduced recoil and cost while familiarizing cadets with bolt-action operation.
FAQs
- What bullet diameter is .303/25 Cadet?
- .303/25 Cadet uses a 0.257″ (6.528 mm) diameter bullet.
- Is .303/25 Cadet still in production?
- .303/25 Cadet is discontinued; typical availability is rare.
Sources & provenance
- Reference Gun Digest / Krause (F+W Media) — Cartridges of the World — Australian .303 wildcats section · bullet ⌀, grain weights
- Secondary Wolfe Publishing (loaddata.com) — Nick Harvey's Practical Reloading Manual — Reloading Data — .303/.25 Australian Wildcat (Metallic) · bullet ⌀, velocity, grain weights archived
- Secondary Cartridges based on the .303 British — CartridgeCollector.net · parent_cartridge
- Secondary .25-303 — Ballistic Studies Knowledgebase · parent_cartridge
Data & sources. Specs compiled from the Lindcott Armory reference; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →