Hunting construction
Soft-point, bonded, partitioned, and monolithic expanding bullets are designed differently. Their intended impact-velocity ranges and use cases come from the bullet or ammunition manufacturer.
THE CARTRIDGE LIBRARY · SPORTING & MATCH RIFLE
.303 British
A rimmed service-rifle cartridge with a .303 historical designation. Its bullet specification differs from common .308-diameter sporting cartridges.
2A Ledger reference desk · Sources checked October 18, 2026
Read the dimensions
- Overall · min–max
- 2.915–3.075 in
74.041–78.105 mm - Case length · max
- 2.222 in
56.439 mm - Bullet maximum
- 0.3125 in
7.938 mm - Rim diameter · max
- 0.540 in
13.716 mm
Know the exact name
At a glance
- Cartridge family
- Sporting & match rifle
- Bullet specification
- 0.3125 in / 7.938 mmBullet maximum
- Factory examples
- 3 loadsSelected, sourced examples below
- Weight in cited examples
- 150–180 grGrains measure mass, not powder charge
.303 British is identified by its complete cartridge designation. The resource-table alternative is 303 British. A caliber number, bullet diameter, or family resemblance on its own does not identify ammunition compatibility.
Do not infer bullet diameter from the .303 name. Older rifles may also require individual condition and ammunition checks.
Dimensions: open the exact dimensional drawing ↗. The displayed number is bullet maximum, rather than an assertion that every manufactured projectile or barrel has this exact diameter.
Origins & evolution
Background & development
Britain adopted the .303 in 1888, at the transition between black-powder and smokeless military ammunition. Its earliest loading used a heavy round-nose bullet and compressed black powder. The subsequent move to cordite allowed the cartridge family to continue through a major change in military propellant technology.
The .303 later served through both world wars in successive British and Commonwealth rifles and machine guns. Its familiar later military form used a pointed bullet, showing how much the ammunition evolved while retaining the same basic cartridge identity. Military surplus rifles then carried it into civilian sporting use, particularly in places such as Canada and Australia. The result is a history broader than the Lee-Enfield alone: the .303 connects nineteenth-century ammunition development, two world wars, Commonwealth service and the later sporting lives of military rifles.
Historical sources: Sierra: .303 British cartridge history ↗
Construction changes the story
Loads, variations & specialty offerings
Match construction
Open-tip match and tipped match bullets prioritize consistency and aerodynamics. A match designation does not by itself mean the projectile was designed for hunting expansion.
Specialty offerings
Lead-free, reduced-recoil, and premium long-range products are separate load designs when offered. Compare the exact SKU, bullet weight, test barrel, and intended role rather than relying on a cartridge-wide average.
In the cited .303 British examples, bullet weights are 150, 180 grains. These are the weights actually present in this source selection, not a claim that every possible loading is listed.
Bullet construction background: Hornady: anatomy of a bullet ↗. Exact product descriptions and velocities are cited in the factory table.
From the factory catalog
150 grains
2,690 fps
SP
180 grains
2,460 fps
SP
Compare all 3 cited factory load records
| Maker / product | Bullet mass | Published construction | Muzzle velocity | Test barrel | Source |
|---|---|---|---|---|---|
| Federal303B | 150 gr 9.72 g | SP | 2,690 fps 820 m/s | 24 in | Federal · PDF pp. 56–57 ↗ |
| Hornady8225 | 150 gr 9.72 g | InterLock® SP | 2,685 fps 818 m/s | Not stated here; see source | Hornady · PDF p. 187 ↗ |
| Federal303AS | 180 gr 11.66 g | SP | 2,460 fps 750 m/s | 24 in | Federal · PDF pp. 56–57 ↗ |
Explore the published data
Ballistics you can inspect
Select a legend entry to add or remove its line. Hover or tap a plotted point, or use the position slider. With the graph focused, arrow keys move the inspector. Solid dots identify source points; dashed connectors show estimates between them. Load construction, pressure category, and test setup can differ even at the same grain weight.
Read the original values as accessible tables
.303 British: factory velocity downrange
| Exact load | Source | Published points |
|---|---|---|
| 150 gr Federal SP | Federal | 0: 2690; 100: 2442; 200: 2208; 300: 1988; 400: 1780; 500: 1590 |
| 180 gr Federal SP | Federal | 0: 2460; 100: 2206; 200: 1966; 300: 1744; 400: 1542; 500: 1363 |
| 150 gr Hornady InterLock® SP | Hornady | 0: 2685; 100: 2441; 200: 2211; 300: 1993; 400: 1789; 500: 1601 |
How to interpret the comparison
Changing bullet weight also often changes bullet design and propellant choice. Two curves are comparisons of the listed products, not a controlled experiment proving that bullet weight alone caused the difference. Catalog downrange points are projections under the maker’s conditions; barrel-study points are recorded observations in the study firearm.
Direct answers
Common questions
What is .303 British?
A rimmed service-rifle cartridge with a .303 historical designation. Its bullet specification differs from common .308-diameter sporting cartridges.
What diameter does .303 British use?
The cited dimensional standard lists 0.3125 inches (7.938 mm), bullet maximum. This drawing convention is different from a casual caliber nickname.
Are similarly named cartridges interchangeable?
Do not infer bullet diameter from the .303 name. Older rifles may also require individual condition and ammunition checks.
Are the graph values measured or estimated?
The downrange view uses the exact manufacturer catalog records shown in the source table. Dashed connectors and intermediate inspector values use linear interpolation between the displayed source points. Calculated energy uses the listed bullet mass and velocity.
Does higher energy mean the best load?
Energy is calculated from mass and velocity. It does not establish accuracy, expansion, penetration, pattern density, recoil, or suitability for a particular firearm. Use the exact product documentation and firearm manual.
Trace the facts
Sources & methodology
Compiled by 2A Ledger from the linked standards, manufacturer publications, and identified test records. Checked October 18, 2026. Historical tests and older catalogs retain their original dates; a listing here does not establish current availability.
- SAAMI: dimensional drawing · PDF p. 127 ↗
- Sierra: .303 British cartridge background ↗
- Federal · PDF pp. 56–57 ↗
- Hornady · PDF p. 187 ↗
Diameter figures preserve the cited drawing convention. Inch–millimeter conversion uses exactly 25.4 mm per inch. Factory specifications describe the maker’s test setup; your firearm, ammunition lot, temperature, and measuring method can produce different results. This is an educational factory-ammunition reference, not a reloading manual.