The .308 Norma Magnum (also .30-338 Magnum)
By Chuck Hawks
For years wildcatters had been shortening the .300 H&H case so that it would feed through standard (.30-06) length bolt actions. The introduction of the standard length .338 Win. Mag. in 1958 was a boon to wildcatters, as it could simply be necked down to .30 caliber to create the .30-338 Magnum.
In 1960 Norma of Sweden became the first major company to put their name on a standard length .30 Magnum cartridge. The .308 Norma Magnum is based on a .338 Win. Mag. case necked down to accept .308" diameter bullets. It is virtually identical to the .30-338 Mag. wildcat. The maximum case length is 2.559", the maximum cartridge overall length is 3.345", the rim diameter is .532", the shoulder angle is 25.5 degrees, and the neck is .317" long (more than one bullet diameter). The established maximum mean pressure for the .308 Mag. is 55,100 psi.
By 1962 .308 Norma factory loaded ammo was being imported into the U.S. This fine cartridge might well have been a major commercial success but for the fact that the .300 Winchester Magnum, with slightly larger case capacity and therefore slightly greater performance, was introduced just a year later. The domestic product quickly overshadowed the Swedish cartridge.
The .308 Norma Mag. is not currently loaded by the big U.S. ammo companies, but it is still available from Norma. Norma factory loads for the .308 Magnum drive a 200 grain Vulkan bullet to a muzzle velocity (MV) of 2903 fps and muzzle energy (ME) of 3744 ft. lbs. At 200 yards the velocity is 2361 fps and the kinetic energy is 2476 ft. lbs. The trajectory of that load looks about like this: +2.8" at 100 yards, +2" at 200 yards, and -5" at 300 yards.
Reloaders can essentially equal the Norma factory load. Or, according to the 26th edition of the Hodgdon Data Manual they can drive a 150 grain bullet to a MV of 3090 fps with 79.0 grains of H1000 powder, and 3279 fps with 83.0 grains of H1000. A 165 grain bullet can be driven to MV of 2939 fps by 75.0 grains of H1000 powder, and 3123 fps by 79.0 grains of H1000. A 180 grain bullet can achieve a MV of 2769 fps in front of 72.0 grains of H1000 powder, and 2940 fps in front of 76.0 grains of the same powder. Hodgdon reports a pressure of 51,900 cup for the latter load. Velocities for all of the above loads were measured in a 26" barrel.
The reloader will find that the .308 Norma will handle bullets of 180 grains and heavier every bit as well as (or better than) the .300 Win. Magnum, and considerably better than the new short .300 WSM and .300 Rem. SAUM cartridges. Unfortunately, it has never gained the popularity it deserves. Due to its combination of standard length, a longer neck than most of its competitors, and excellent Norma brass, the .308 Norma Magnum may be the all-around best .300 Magnum cartridge for the dedicated reloader.
Copyright 2002, 2012 by Chuck Hawks. All rights reserved.