Lindcott Armory 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
- 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
- ReferenceGun Digest / Krause (F+W Media) — Cartridges of the World — Australian .303 wildcats section · bullet ⌀, grain weights
- SecondaryWolfe Publishing (loaddata.com) — Nick Harvey's Practical Reloading Manual — Reloading Data — .303/.25 Australian Wildcat (Metallic) · bullet ⌀, velocity, grain weightsarchived
- SecondaryCartridges 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 →