.338 Winchester Magnum

Rifle cartridge

The .338 Winchester Magnum is a caliber, belted, rimless, bottlenecked cartridge introduced in 1958 by Winchester Repeating Arms. It is based on the blown out, shortened .375 H&H Magnum. The is the caliber at which medium bore cartridges are considered to begin. The .338 Winchester Magnum is the first choice among professional brown bear (specifically grizzly bear) guides in Alaska to back up clients where a powerful stopping caliber is required on charging bears. It is also the most popular medium bore cartridge in North America and has the most widely available choice in rifles among medium bore rifles. The action length is the same as a .30 06, and most major rifle manufacturers in the United States chamber rifles for the cartridge including the semi automatic Browning BAR Mk II Safari, making it a very powerful combination against charging dangerous game. The cartridge was intended for larger North American big game species and has found use as for the hunting of thin skinned African plains game species. providing energy values at 200 yards that are roughly equivalent to the .30 06 Springfield's energy values at muzzle. Bullets are available in a very wide range of designs and weights ranging from 150 to 300 grains. SAAMI pressure level is 64,000 psi. The .338 Winchester Magnum is capable of launching heavier bullets than the .30 caliber (7.62mm) cartridges. The most common bullets loaded for the .338 Winchester range from to Typical bullet weights for factory ammunition are , , and the Typical velocities for these bullet weights range from for the to about for the bullet each generating approximately of energy. This is approximately 25% more energy generated than the 30 06 Springfield. Winchester's Ballistic Silvertip ammunition (SBST338) retains over at and has energy at Winchester's Combined Technologies Accubond ammunition (S338CT) extend the range for these energy levels even further to and respectively. Hornady's SST Superformance load has muzzle energy of @ 3030fps. It maintains @ 2068fps @ 500 meters. Hornady's SST Superformance load has muzzle energy of @ 2840fps. It maintains @ 2014fps @ 500 meters. This is from a 24" test barrel as compared to 27.5" test barrel for a 338 Lapua. Figures would be higher if shot from a 27.5" test barrel but still over 150fps slower than a 338 Lapua if tested with the same length barrel. The recoil of this caliber is quite heavy, with about of recoil energy in a rifle. This is about twice as much as the recoil from an average .308 Winchester. Strong recoil like this can be mitigated with the use of properly designed stocks and recoil pads. By comparison, this cartridge has less recoil than other more powerful .338 caliber rifles such as the .338 RUM, .340 Weatherby and .338 Lapua.

When the .338 Winchester was introduced there was a general preference for heavier bullet weights between However, since that time preferred bullet weights have decreased to weights between This is due in part to the bullet technology available today. Lighter bullets made today are able to hold together and penetrate deeper than heavier bullets of the past. In North America, the .338 Winchester Magnum is most commonly used for the hunting of larger deer species such as elk and moose. It is quite popular with elk hunters, with bullets ranging between generally preferred for large class 3 game such as elk or moose. The .338 Winchester Magnum can be considered a good all round plains game hunting rifle in Africa. It has also been found to be effective against the big cats where hunting allows for the use of the cartridge.

Due to the cartridge's popularity all North American rifle manufacturers offer rifles chambered in the .338 Winchester Magnum. Ruger, Browning, Kimber, Remington, Savage, Weatherby, Mossberg, Howa and Winchester chamber the cartridge in several product lines. Almost all custom rifle makers in the United States and Canada produce .338 Winchester rifles. In European rifle makers Blaser, Mauser, Sako and Tikka also manufacture rifles for this cartridge. The large number of rifle choices available in the .338 Winchester Magnum offers the rifleman a greater choice in available rifles. All North American ammunition makers offer several loadings of the .338 Winchester Magnum to the public for sale. At this point in time Federal has six in their Vital Shok and Fusion ammunition lines, Hornady has five, including four in their Superformance ammunition which is putting an end to the light magnum and heavy magnum line of ammo but adds up to more without added recoil or muzzle blast. The 185 gr. GMX (gilding metal expanding) round has the following performance: at the muzzle, at 100 yards, of kinetic energy at the muzzle and at 100 yards. 200 gr. Remington and Winchester offer four loadings each for the cartridge. Several smaller ammunition including Cor Bon and Double Tap also manufacture loaded ammunition.