Traditional sporting bullets
Flat-nose, round-nose, and soft-point designs remain important in these cartridge families. For tubular magazines, use ammunition specifically approved by the manufacturer.
THE CARTRIDGE LIBRARY · LARGE-BORE CENTERFIRE
.458 Winchester Magnum
A belted .458-caliber sporting magnum intended for large-bore rifles. Solid and expanding factory projectiles serve different purposes.
2A Ledger reference desk · Sources checked October 18, 2026
Read the dimensions
- Overall · min–max
- 3.280–3.340 in
83.312–84.836 mm - Case length · max
- 2.500 in
63.500 mm - Bullet maximum
- 0.459 in
11.659 mm - Rim diameter · max
- 0.532 in
13.513 mm
Know the exact name
At a glance
- Cartridge family
- Large-bore centerfire
- Bullet specification
- 0.4590 in / 11.659 mmBullet maximum
- Factory examples
- 6 loadsSelected, sourced examples below
- Weight in cited examples
- 400–500 grGrains measure mass, not powder charge
.458 Winchester Magnum is identified by its complete cartridge designation. The resource-table alternative is 458 Win Mag. A caliber number, bullet diameter, or family resemblance on its own does not identify ammunition compatibility.
A solid bullet, a monolithic expanding bullet, and a soft point are different constructions. The .458 diameter alone does not describe their behavior.
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
Winchester introduced the .458 Magnum in 1956 as a modern bolt-action alternative to the large British Nitro Express sporting cartridges. Its aim was to provide dangerous-game performance in a standard .30-06-length rifle action, using a belted case rather than the large rimmed cases traditionally associated with double rifles.
That rifle-and-ammunition package helped it find a substantial audience among African professional hunters, game-control personnel and sportsmen. It also appeared in Alaska and in the collections of shooters interested in powerful sporting rifles. Its influence went beyond its own sales: it formed part of Winchester’s postwar magnum program and became a reference point for later large-bore cartridges. The .458’s historical significance is the attempt to make a factory-produced American bolt-action rifle serve a role previously dominated by specialized British dangerous-game systems.
Historical sources: Sierra: .458 Winchester Magnum cartridge history ↗
Construction changes the story
Loads, variations & specialty offerings
Purpose-built modern loads
Flexible tips, bonded bullets, monolithic expanding bullets, and solids have different functions. A similar exterior shape or shared diameter does not establish equivalent behavior.
Firearm-specific ammunition
Some older cartridge families span firearms with very different operating limits. Keep any product restrictions with the ammunition record and use only loads authorized for that firearm.
In the cited .458 Winchester Magnum examples, bullet weights are 400, 500 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
400 grains
2,250 fps
TROPHY BONDED BEAR CLAW
500 grains
2,090 fps
SWIFT A-FRAME
Compare all 6 cited factory load records
| Maker / product | Bullet mass | Published construction | Muzzle velocity | Test barrel | Source |
|---|---|---|---|---|---|
| FederalP458T1 | 400 gr 25.92 g | TROPHY BONDED BEAR CLAW | 2,250 fps 686 m/s | 24 in | Federal · PDF pp. 54–55 ↗ |
| FederalP458SA | 500 gr 32.40 g | SWIFT A-FRAME | 2,090 fps 637 m/s | 24 in | Federal · PDF pp. 54–55 ↗ |
| FederalP458T2 | 500 gr 32.40 g | TROPHY BONDED BEAR CLAW | 2,090 fps 637 m/s | 24 in | Federal · PDF pp. 54–55 ↗ |
| FederalP458T3 | 500 gr 32.40 g | TROPHY BONDED SLEDGEHAMMER SOLID | 1,950 fps 594 m/s | 24 in | Federal · PDF pp. 54–55 ↗ |
| Hornady85834 | 500 gr 32.40 g | DGX® Bonded SPF | 2,140 fps 652 m/s | Not stated here; see source | Hornady · PDF p. 189 ↗ |
| Hornady8585 | 500 gr 32.40 g | DGS® SPF | 2,140 fps 652 m/s | Not stated here; see source | Hornady · PDF p. 189 ↗ |
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
.458 Winchester Magnum: factory velocity downrange
| Exact load | Source | Published points |
|---|---|---|
| 400 gr Federal TROPHY BONDED BEAR CLAW | Federal | 0: 2250; 100: 2025; 200: 1813; 300: 1619; 400: 1442; 500: 1290 |
| 500 gr Federal SWIFT A-FRAME | Federal | 0: 2090; 100: 1878; 200: 1683; 300: 1503; 400: 1345; 500: 1212 |
| 500 gr Federal TROPHY BONDED BEAR CLAW | Federal | 0: 2090; 100: 1822; 200: 1580; 300: 1369; 400: 1198; 500: 1076 |
| 500 gr Federal TROPHY BONDED SLEDGEHAMMER SOLID | Federal | 0: 1950; 100: 1729; 200: 1528; 300: 1352; 400: 1205; 500: 1096 |
| 500 gr Hornady DGX® Bonded SPF | Hornady | 0: 2140; 100: 1880; 200: 1643; 300: 1432 |
| 500 gr Hornady DGS® SPF | Hornady | 0: 2140; 100: 1880; 200: 1643; 300: 1432 |
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 .458 Winchester Magnum?
A belted .458-caliber sporting magnum intended for large-bore rifles. Solid and expanding factory projectiles serve different purposes.
What diameter does .458 Winchester Magnum use?
The cited dimensional standard lists 0.4590 inches (11.659 mm), bullet maximum. This drawing convention is different from a casual caliber nickname.
Are similarly named cartridges interchangeable?
A solid bullet, a monolithic expanding bullet, and a soft point are different constructions. The .458 diameter alone does not describe their behavior.
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. 172 ↗
- Sierra: .458 Winchester Magnum cartridge background ↗
- Federal · PDF pp. 54–55 ↗
- Hornady · PDF p. 189 ↗
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.