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
.257 Weatherby Magnum
A belted .25-caliber magnum sporting cartridge, distinct from both .257 Roberts and .25-06 Remington. Weatherby factory data commonly uses a long test barrel.
2A Ledger reference desk · Sources checked October 18, 2026
Read the dimensions
- Overall · min–max
- 3.049–3.209 in
77.445–81.509 mm - Case length · max
- 2.549 in
64.745 mm - Bullet maximum
- 0.2573 in
6.535 mm - Rim diameter · max
- 0.5315 in
13.500 mm
Know the exact name
At a glance
- Cartridge family
- Sporting & match rifle
- Bullet specification
- 0.2573 in / 6.535 mmBullet maximum
- Factory examples
- 7 loadsSelected, sourced examples below
- Weight in cited examples
- 90–120 grGrains measure mass, not powder charge
.257 Weatherby Magnum is identified by its complete cartridge designation. The resource-table alternative is 257 Wby Mag. A caliber number, bullet diameter, or family resemblance on its own does not identify ammunition compatibility.
The graphs retain the 26-inch barrel specified in the cited Weatherby chart. Shorter-barrel estimates are labeled separately.
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
Roy Weatherby developed the .257 Weatherby Magnum during the early 1940s; Sierra dates its introduction to 1944. Like several of his early designs, it drew on the .300 Holland & Holland belted case family, but in a shortened form suited to its .25-caliber bullet.
The cartridge expresses Weatherby’s original sporting philosophy particularly clearly: obtain very high velocity from a relatively small bullet to produce a flat-shooting open-country rifle. That distinguished it from moderate .25-caliber cartridges such as the .257 Roberts and, later, from the commercially standardized .25-06 Remington. Its history is also inseparable from Weatherby rifles and factory ammunition, which kept a relatively specialized design available as a coordinated system. Although the word magnum has been used on many very different cartridges, the .257 Weatherby’s place in the early Weatherby family reflects a specific high-velocity design tradition.
Historical sources: Sierra: .257 Weatherby Magnum 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 .257 Weatherby Magnum examples, bullet weights are 90, 100, 110, 115, 120 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
90 grains
3,625 fps
CX®
100 grains
3,570 fps
Barnes TTSX
110 grains
3,240 fps
ELD-X®
Compare all 7 cited factory load records
| Maker / product | Bullet mass | Published construction | Muzzle velocity | Test barrel | Source |
|---|---|---|---|---|---|
| Hornady813624 | 90 gr 5.83 g | CX® | 3,625 fps 1,105 m/s | Not stated here; see source | Hornady · PDF p. 184 ↗ |
| WeatherbyB257100TTSX | 100 gr 6.48 g | Barnes TTSX | 3,570 fps 1,088 m/s | 26 in | Weatherby · PDF p. 1 ↗ |
| Hornady81364 | 110 gr 7.13 g | ELD-X® | 3,240 fps 988 m/s | Not stated here; see source | Hornady · PDF p. 184 ↗ |
| WeatherbyH257110ELDX | 110 gr 7.13 g | ELD-X | 3,400 fps 1,036 m/s | 26 in | Weatherby · PDF p. 1 ↗ |
| WeatherbyN257110ACB | 110 gr 7.13 g | Accubond | 3,460 fps 1,055 m/s | 26 in | Weatherby · PDF p. 1 ↗ |
| WeatherbyN257115BST | 115 gr 7.45 g | Ballistic Tip | 3,400 fps 1,036 m/s | 26 in | Weatherby · PDF p. 1 ↗ |
| WeatherbyN257120PT | 120 gr 7.78 g | Partition | 3,305 fps 1,007 m/s | 26 in | Weatherby · PDF p. 1 ↗ |
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
.257 Weatherby Magnum: estimated shorter-barrel scenarios
| Exact load | Source | Published points |
|---|---|---|
| 100 gr Barnes TTSX · 30 fps/in scenario | Weatherby 2020 rule; calculated scenario | 16: 3270; 17: 3300; 18: 3330; 19: 3360; 20: 3390; 21: 3420; 22: 3450; 23: 3480; 24: 3510; 25: 3540; 26: 3570 |
| 100 gr Barnes TTSX · 65 fps/in scenario | Weatherby 2020 rule; calculated scenario | 16: 2920; 17: 2985; 18: 3050; 19: 3115; 20: 3180; 21: 3245; 22: 3310; 23: 3375; 24: 3440; 25: 3505; 26: 3570 |
.257 Weatherby Magnum: factory velocity downrange
| Exact load | Source | Published points |
|---|---|---|
| 90 gr Hornady CX® | Hornady | 0: 3625; 100: 3230; 200: 2871; 300: 2539; 400: 2230; 500: 1944 |
| 100 gr Weatherby Barnes TTSX | Weatherby | 0: 3570; 100: 3269; 200: 2989; 300: 2726; 400: 2478; 500: 2243 |
| 110 gr Hornady ELD-X® | Hornady | 0: 3240; 100: 3024; 200: 2819; 300: 2623; 400: 2435; 500: 2255 |
| 115 gr Weatherby Ballistic Tip | Weatherby | 0: 3400; 100: 3170; 200: 2952; 300: 2745; 400: 2547; 500: 2357 |
| 120 gr Weatherby Partition | Weatherby | 0: 3305; 100: 3046; 200: 2801; 300: 2570; 400: 2350; 500: 2141 |
| 110 gr Weatherby ELD-X | Weatherby | 0: 3400; 100: 3176; 200: 2964; 300: 2762; 400: 2569; 500: 2384 |
| 110 gr Weatherby Accubond | Weatherby | 0: 3460; 100: 3207; 200: 2969; 300: 2744; 400: 2529; 500: 2325 |
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 .257 Weatherby Magnum?
A belted .25-caliber magnum sporting cartridge, distinct from both .257 Roberts and .25-06 Remington. Weatherby factory data commonly uses a long test barrel.
What diameter does .257 Weatherby Magnum use?
The cited dimensional standard lists 0.2573 inches (6.535 mm), bullet maximum. This drawing convention is different from a casual caliber nickname.
Are similarly named cartridges interchangeable?
The graphs retain the 26-inch barrel specified in the cited Weatherby chart. Shorter-barrel estimates are labeled separately.
Are the graph values measured or estimated?
The downrange view uses the exact manufacturer catalog records shown in the source table. The estimated barrel-length view applies the disclosed Weatherby slope rule to the 26-inch catalog anchor; it is a calculated scenario. 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. 95 ↗
- Sierra: .257 Weatherby Magnum cartridge background ↗
- Hornady · PDF p. 184 ↗
- Weatherby · PDF p. 1 ↗
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.