The .30-40 Krag, An Old School round that still has the right stuff!

.30-40 Krag
30-40 Krag cartridges.JPG
Type Rifle
Place of origin United States
Service history
In service Army
Used by United States
Production history
Designed 1892
Specifications
Case type Rimmed, bottleneck
Bullet diameter .308 in (7.8 mm)
Neck diameter .338 in (8.6 mm)
Shoulder diameter .423 in (10.7 mm)
Base diameter .457 in (11.6 mm)
Rim diameter .545 in (13.8 mm)
Rim thickness .064 in (1.6 mm)
Case length 2.314 in (58.8 mm)
Overall length 3.089 in (78.5 mm)
Case capacity 58.0 gr H2O (3.76 cm3)
Maximum pressure (C.I.P.) 47,137 psi (325.00 MPa)
Maximum pressure (SAAMI) not established
Maximum CUP 40,000 CUP
Ballistic performance
Bullet mass/type Velocity Energy
100 gr (6 g) SP 2,898 ft/s (883 m/s) 1,865 ft⋅lbf (2,529 J)
130 gr (8 g) HP 2,746 ft/s (837 m/s) 2,177 ft⋅lbf (2,952 J)
150 gr (10 g) Nos Part 2,575 ft/s (785 m/s) 2,209 ft⋅lbf (2,995 J)
180 gr (12 g) SP 2,276 ft/s (694 m/s) 2,071 ft⋅lbf (2,808 J)
200 gr (13 g) RN 1,974 ft/s (602 m/s) 1,731 ft⋅lbf (2,347 J)
Source(s): Hodgdon [1]

From the outset, the .30-40 cartridge proved popular for hunting, and was chambered in a variety of firearms. In 1899, a Krag in .30-40 caliber was used to shoot the world-record Rocky Mountain elk. The record stood until the latter half of the 20th century.

In October 1899, after reviewing the experiences of the Spanish–American War, U.S. Army ordnance authorities developed a new loading for the .30 Army used in the Krag rifle, in an attempt to match the ballistics of the 7×57mm Mauser cartridge employed by Spanish forces in that conflict. The new loading increased the muzzle velocity in the rifle version of the Krag to 2,200 ft/s (670 m/s) at 45,000 psi. However, once the new loading was issued, reports of cracked locking lugs on service Krags began to surface. In March 1900 the remaining stocks of this ammunition (some 3.5 million rounds) were returned to the arsenals, broken down, and reloaded back to the original 2,000 ft/s (610 m/s) specification.

In 1903, after recommendations from the infantry Small Arms Board, the U.S. Army formally adopted a higher-velocity .30-caliber replacement for the .30-40 or .30 Army cartridge. The new cartridge was designated by its year of adoption, the .30-03.

Rifles, handguns, and other weapons chambered in .30-40 Krag[edit]

A replica of the McKeever-pattern .30 US Army cartridge case.

See also[edit]

References[edit]

  1. Jump up^ .30-40 data at Hodgdon Online
  2. Jump up^ Johnson, Melvin M., Jr. (1944). Rifles and Machine Guns. New York: William Morrow & Company. p. 384.
  3. Jump up^ History of Winchester Firearms, 1866-1992, Thomas Henshaw, p 44-45