300 Win Mag

The .300 Winchester Magnum (also known as .300 Win Mag or 300WM) (7.62x67mm) is a popular, belted, bottlenecked magnum rifle cartridge that was introduced by Winchester Repeating Arms Company in 1963 as a member of the family of Winchester Magnum cartridges. The .300 Winchester Magnum is a magnum cartridge designed to fit in a standard length action. It is based on the .375 H&H Magnum, which has been blown out, shortened, and necked down to accept a .30 caliber (7.62 mm) bullet.

The .300 Winchester is extremely versatile and has been adopted by a wide range of users including hunters, target shooters, military units, and law enforcement departments. Hunters found the cartridge to be an effective all-around choice with bullet options ranging from the flatter shooting 165 grain to the harder hitting 200+ grain selections available from the factory. The .300 Win Mag remains the most popular .30 caliber magnum with North American hunters, despite being surpassed in performance by the more powerful .300 Weatherby Magnum and the newer .300 Remington Ultra Magnum. It is a popular selection for hunting moose, elk, and bighorn sheep as it can deliver better long range performance with better bullet weight than most other .30 caliber cartridges. Military and law enforcement departments adopted the cartridge for long range sniping and marksmanship. As a testament to its accuracy, since its introduction it has gone on to win several 1,000-yard (910 m) competitions

Suggested Use

• Deer (long range)
• Black Bear (long range)
• Sheep / Goat (long range)
• Moose
• Elk
• Buffalo / Bison

Performance

The Winchesters factory ammunition for the .300 Winchester Magnum is capable of 3,260 feet per second (990 m/s) with the 150-grain (9.7 g) bullet and 3,000 ft/s (910 m/s) with the 180-grain (12 g) bullet. The maximum point blank range for the 150 gr (9.7 g) bullet is 318 yards (291 m) yards when zeroed at 270 yards (250 m). The maximum point blank range for the 180 gr (12 g) bullet is 300 yards when zeroed at 254 yards (232 m). The ability to zero the .300 Winchester Magnum and shoot without hold over to 300 yards (270 m) makes the cartridge one of the flatter shooting cartridges.

The .30 caliber is the most popular caliber in the United States. So it is not surprising that the widest range of bullets available is in the .30 caliber. The most useful bullet weights for the .300 Winchester Magnum are those weighing between 150 to 200 grains (9.7 to 13.0 g). However, bullets weighing between 110 to 250 gr (7.1 to 16.2 g) are available to the reloader for the .300 Winchester Magnum.

Compared with the 30-06 Springfield the .300 Winchester Magnum provides a nearly 300 ft/s (91 m/s) increase in velocity. This translates to about 20% greater energy advantage over the 30-06 Springfield cartridge. Due to the short neck, heavier bullets particularly those weighing greater than 200 grains (13 g) and mono-metal bullets such as the Barnes X bullets will need to be seated more deeply into the cartridge. As the bullet will take up volume which could have been taken by the propellant velocity advantages diminish as the weight of the bullet increases.

The .300 Winchester Magnum is known for its accuracy and has been used for 1,000-yard (910 m) and 1,000-metre (1,100 yd) competitions. While in hunting situations such accuracy is unnecessary, such accuracy does aid in the extending the range of the cartridge. Taken together with its performance it remains one of the most useful and popular cartridges today.

Although cartridges such as the .30-378 Weatherby Magnum, .300 Remington Ultra Magnum and the .300 Weatherby Magnum all exceed performance of the .300 Winchester Magnum none of these cartridges can be chambered in a standard length action. Few .30 caliber (7.62 mm) standard length cartridges can match the performance and versatility of the .300 Winchester Magnum.

The down side to this performance is recoil. The amount of recoil the cartridge generates is a step up from the non-magnum .30 caliber (7.62 mm) cartridges. Its recoil is about 30% greater than that of the .30-06 Springfield, which is known as a 'stout' cartridge. This would put the .300 Winchester Magnum at the upper limit of what most shooters can shoot comfortably for extended shooting sessions. As a rough comparison, the recoil of the .300 Winchester Magnum is roughly comparable to a 12 gauge shotgun shooting 1 oz. slugs. This greater recoil can make the .300 Winchester Magnum, despite its inherent accuracy advantages, a harder cartridge to shoot accurately, when compared to non-magnum .30 caliber cartridges such as the .30-06 Springfield or the .308 Winchester. On the other hand, recoil is subjective (some are more sensitive to it than others) and one can get used to it with practice. Also, many rifles available today now have effective recoil attenuating features built into them, such as muzzle compensators and energy absorbing stocks and butt-pads, that can significantly lessen recoil as it is felt by the shooter.