.340 Weatherby Magnum

.340 Weatherby Magnum
340 Weatherby with 308 and 9mm.jpg
A .340 Weatherby Magnum cartridge between a .308 Winchester cartridge and a 9×19mm cartridge
Place of originUnited States
Production history
DesignerRoy Weatherby
Produced1963 to present
Parent case.300 H&H Magnum, full length
Case typeRimless, bottlenecked with venturi shoulder
Bullet diameter.338 in (8.6 mm)
Neck diameter.366 in (9.3 mm)
Shoulder diameter.495 in (12.6 mm)
Base diameter.513 in (13.0 mm)
Rim diameter.530 in (13.5 mm)
Rim thickness.048 in (1.2 mm)
Case length2.82 in (72 mm)
Overall length3.6 in (91 mm)
Case capacity98 gr H2O (6.4 cm3)
Primer typelarge rifle magnum
Ballistic performance
Bullet mass/type Velocity Energy
200 gr (13 g) SP 3,221 ft/s (982 m/s) 4,607 ft⋅lbf (6,246 J)
225 gr (15 g) SP 3,066 ft/s (935 m/s) 4,696 ft⋅lbf (6,367 J)
250 gr (16 g) SP 2,963 ft/s (903 m/s) 4,873 ft⋅lbf (6,607 J)
Source(s): Weatherby [1]

The .340 Weatherby Magnum rifle cartridge was introduced in 1962 by creator Roy Weatherby to fill the gap between the .300 Weatherby Magnum and the .378 Weatherby Magnum, and in response to the .338 Winchester Magnum released in 1958.[2][1]

The .340 Weatherby Magnum uses the same .338 in. diameter bullets as the .338 Winchester Magnum, but it does so at greater velocity than its Winchester competition. Reloaders may have trouble matching the published Weatherby velocities as Weatherby factory ammunition is loaded to maximum specifications.[3] Weatherby no longer loads the 250gr. round-nose cartridge pictured but continues to load the 250 gr. Spire Point and 250 gr. Nosler Partition. Weatherby has also expanded their factory loads including Nosler Ballistic-tip and Barnes TSX bullets complementing the powerful cartridge.[4] Currently A-square is the only other factory ammunition producer of the .340 Weatherby Magnum, which has led to limited popularity of the caliber. In field tests the .340 clearly outperforms the 300 Ultra mag, .338 Win mag. and even rivals the larger .375 H&H, providing a much flatter shooting and harder hitting performance.

This cartridge is powerful enough for even the largest North American game and is suitable for most African game as well.[5]

See also[]


  1. ^ a b Weatherby Inc. .340 Weatherby Magnum information page Archived 2008-06-15 at the Wayback Machine
  2. ^ Bullets, Speer (2009). Speer Bullets Reloading Manual #14. Speer. pp. 602, 608. ISBN 978-0-9791860-0-4.
  3. ^ "The .340 Weatherby Mag" by Chuck Hawks
  4. ^ Weatherby, Inc. | Rifles, Shotguns, Ammunition, Accessories
  5. ^ Barnes, Frank C. (2006) [1965]. Skinner, Stan (ed.). Cartridges of the World (11th ed.). Iola, WI, USA: Gun Digest Books. p. 78. ISBN 0-89689-297-2.