.30-378 Weatherby Magnum

.30-378 Weatherby Magnum
Left, with .300 Weatherby Magnum (center) and .30-06
TypeRifle
Place of originUSA
Production history
DesignerRoy Weatherby
Designed1959
ManufacturerWeatherby Inc.
Produced1996 - Current
Variants.30-.378 Magnum, .30/378 Arch, .30/378 Weatherby
Specifications
Parent case.378 Weatherby Magnum
Case typebelted magnum
Bullet diameter.308 in (7.8 mm)
Neck diameter.337 in (8.6 mm)
Shoulder diameter.561 in (14.2 mm)
Base diameter.582 in (14.8 mm)
Rim diameter.579 in (14.7 mm)
Case length2.913 in (74.0 mm)
Overall length3.690 in (93.7 mm)
Case capacity133 gr H2O (8.6 cm3)
Rifling twist1 in 10 in (250 mm)
Primer typeLarge rifle magnum
Maximum pressure63,817 psi (440.00 MPa)
Ballistic performance
Bullet mass/type Velocity Energy
165 gr (11 g) BST 3,500 ft/s (1,100 m/s) 4,488 ft⋅lbf (6,085 J)
180 gr (12 g) BST 3,420 ft/s (1,040 m/s) 4,676 ft⋅lbf (6,340 J)
200 gr (13 g) Partition 3,160 ft/s (960 m/s) 4,434 ft⋅lbf (6,012 J)
Test barrel length: 26" (660 mm)
Source(s): Weatherby [1]

The .30-378 Weatherby Magnum is a .30 caliber, belted, bottle-necked rifle cartridge.[2] The cartridge was developed in response to a US Army military contract in 1959. While still unreleased to the public, the cartridge went on to set world records for accuracy including the first ten 10X in 1,000 yards (910 m) benchrest shooting.[3] It is currently the highest velocity .30 caliber factory ammunition available.

  1. ^ "Ammo info at Weatherby". Archived from the original on 2006-11-10. Retrieved 2006-12-23.
  2. ^ Hawks, Chuck (2002). "The .300 Super Magnums". chuckhawks.com. Guns and Shooting Online. Retrieved November 24, 2013.
  3. ^ Barnes, Frank c. (2012). Cartridges of the World 13Ed. Iola WI: F+W Media Inc. ISBN 978-1-4402-3059-2.