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
.340 Weatherby Magnum
A belted .338-bullet sporting magnum carrying Weatherby's .340 designation. Its double-radius shoulder and long case distinguish it from .338 Winchester Magnum.
2A Ledger reference desk · Sources checked October 18, 2026
Read the dimensions
- Overall · min–max
- 3.585–3.700 in
91.059–93.980 mm - Case length · max
- 2.825 in
71.755 mm - Bullet maximum
- 0.3383 in
8.593 mm - Rim diameter · max
- 0.5315 in
13.500 mm
Know the exact name
At a glance
- Cartridge family
- Sporting & match rifle
- Bullet specification
- 0.3383 in / 8.593 mmBullet maximum
- Factory examples
- 3 loadsSelected, sourced examples below
- Weight in cited examples
- 225–250 grGrains measure mass, not powder charge
.340 Weatherby Magnum is identified by its complete cartridge designation. The resource-table alternative is 340 Wby Mag. A caliber number, bullet diameter, or family resemblance on its own does not identify ammunition compatibility.
The .340 name does not mean a .340-inch bullet. Check the drawing's bullet specification and the complete cartridge name.
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
The .340 Weatherby Magnum appeared in the early 1960s as Weatherby’s higher-velocity .338-caliber sporting offering. It used the full-length .300 Weatherby case family rather than the shorter case associated with the .338 Winchester Magnum. That choice placed it firmly in a longer magnum-action rifle.
The design followed Weatherby’s established commercial philosophy: offer additional velocity in a coordinated rifle-and-ammunition system, accepting the larger rifle package needed to obtain it. The Mark V became its principal factory platform, and the cartridge developed a specialist role among hunters seeking a powerful medium bore for larger game. It should be distinguished from the .338 Winchester Magnum despite their shared bullet diameter. The .340’s historical role was to extend the Weatherby family into that medium-bore territory while retaining the case length, shoulder style and premium-rifle association of the company’s established magnums.
Historical sources: Sierra: .340 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 .340 Weatherby Magnum examples, bullet weights are 225, 250 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
225 grains
2,970 fps
Barnes TSX
250 grains
2,963 fps
SP
Compare all 3 cited factory load records
| Maker / product | Bullet mass | Published construction | Muzzle velocity | Test barrel | Source |
|---|---|---|---|---|---|
| WeatherbyB340225TTSX | 225 gr 14.58 g | Barnes TSX | 2,970 fps 905 m/s | 26 in | Weatherby · PDF p. 3 ↗ |
| WeatherbyH340250SP | 250 gr 16.20 g | SP | 2,963 fps 903 m/s | 26 in | Weatherby · PDF p. 3 ↗ |
| WeatherbyN340250PT | 250 gr 16.20 g | Partition | 2,941 fps 896 m/s | 26 in | Weatherby · PDF p. 3 ↗ |
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
.340 Weatherby Magnum: estimated shorter-barrel scenarios
| Exact load | Source | Published points |
|---|---|---|
| 225 gr Barnes TSX · 30 fps/in scenario | Weatherby 2020 rule; calculated scenario | 16: 2670; 17: 2700; 18: 2730; 19: 2760; 20: 2790; 21: 2820; 22: 2850; 23: 2880; 24: 2910; 25: 2940; 26: 2970 |
| 225 gr Barnes TSX · 65 fps/in scenario | Weatherby 2020 rule; calculated scenario | 16: 2320; 17: 2385; 18: 2450; 19: 2515; 20: 2580; 21: 2645; 22: 2710; 23: 2775; 24: 2840; 25: 2905; 26: 2970 |
.340 Weatherby Magnum: factory velocity downrange
| Exact load | Source | Published points |
|---|---|---|
| 225 gr Weatherby Barnes TSX | Weatherby | 0: 2970; 100: 2786; 200: 2609; 300: 2440; 400: 2276; 500: 2119 |
| 250 gr Weatherby SP | Weatherby | 0: 2963; 100: 2745; 200: 2537; 300: 2338; 400: 2149; 500: 1968 |
| 250 gr Weatherby Partition | Weatherby | 0: 2941; 100: 2743; 200: 2553; 300: 2371; 400: 2197; 500: 2029 |
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 .340 Weatherby Magnum?
A belted .338-bullet sporting magnum carrying Weatherby's .340 designation. Its double-radius shoulder and long case distinguish it from .338 Winchester Magnum.
What diameter does .340 Weatherby Magnum use?
The cited dimensional standard lists 0.3383 inches (8.593 mm), bullet maximum. This drawing convention is different from a casual caliber nickname.
Are similarly named cartridges interchangeable?
The .340 name does not mean a .340-inch bullet. Check the drawing's bullet specification and the complete cartridge name.
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. 143 ↗
- Sierra: .340 Weatherby Magnum cartridge background ↗
- Weatherby · PDF p. 3 ↗
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.