The .300 Winchester Magnum was introduced in 1963 by Winchester for use in the Model 70 rifle. The introduction of the .300 Winchester Magnum was not unforeseen; rather, its introduction was anticlimactic. Winchester developed the .300 Winchester Magnum by taking the .338 Winchester Magnum, which was introduced in 1958, and moved the shoulder forward by 4.0 millimetres (0.156 in) and lengthening it by 3.0 millimetres (0.120 in). This caused the cartridge to have a neck shorter than the diameter of the bullet. There has been some speculation that if the cartridge was released earlier, the dimensions of the cartridge would have matched the .30-338 Winchester wildcat cartridge. Since its introduction the cartridge has remained extremely popular.
The .300 Winchester Magnum’s high availability in popular rifles such as Winchester Model 70, Ruger M77 and Remington Model 700 have made the cartridge a popular choice among hunters and bench shooters. Although the .300 H&H Magnum, .300 Weatherby Magnum, .30-338 Winchester Magnum and the .308 Norma Magnum had a head start on the .300 Winchester Magnum, most of these cartridges faded into obsolescence. Only the .300 Winchester Magnum and the .300 Weatherby Magnum were to survive as readily available cartridges, becoming the .300 Winchester Magnum far more popular despite appearing in the scene 19 years after the latter. New .300 magnum have been introduced to the market such as the .300 Winchester Short Magnu, .300 Remington Ultra Magnum and .30 Nosler and .300 PRC; however, none of these have achieved the popularity that the .300 Win Mag still holds
The Winchester’s factory ammunition for the .300 Winchester Magnum is capable of 990 m/s (3,260 ft/s) with the 150-grain (9.7 g) bullet and 910 m/s (3,000 ft/s) with the 12-gram (180 gr) bullet, however old Western “Power Point” soft point can reach past 1,000 metres per second (3,400 ft/s) with 9.7 g (150 gr) projectiles. The maximum point blank range for the 9.7 g (150 gr) bullet is 291 metres (318 yd) yards when zeroed at 250 metres (270 yd). The maximum point blank range for the 12 g (180 gr) bullet is 300 yards when zeroed at 232 metres (254 yd). The ability to zero the .300 Winchester Magnum and shoot without hold over to 270 metres (300 yd) makes the cartridge one of the flatter shooting cartridges
300 WIN MAG FOR SALE is available on Ammunitionsuplus at affordables prices we carry varities of brands like Federal , Hornady ,Winchester. etc