The .264 Winchester Magnum
By Chuck Hawks
The smallest caliber in Winchester's series of standard length belted magnums, which includes the .264, .300, .338, and .458 Winchester Magnums, the .264 Winchester Magnum (a 6.5mm to Europeans) was designed to be the ultimate ultra-long range big game cartridge. Winchester called it "The Westerner" in their early catalogs.
Factory ballistics for the .264 Mag. have been toned down from the original offerings. Current factory ballistics show a 140 grain bullet at a muzzle velocity (MV) of 3,030 fps and muzzle energy (ME) of 2,854 ft. lbs. The 300 yard figures are 2,326 fps and 1,682 ft. lbs. of energy.
Winchester and Remington used to load the 140 grain bullet to a MV of 3200 fps and ME of 3180 ft. lbs. from a 26" barrel. Those loads gave a mid-range trajectory of approximately 4.9" over 300 yards. A 26" barrel is necessary to get full performance from the .264 Mag.
Naturally, slow burning rifle powders work best in the .264 Mag. H870, IMR 4831, IMR 7828, RL-22, and AA 8700 are all good choices.
Here are some specifications of interest to reloaders: bullet diameter .264", maximum COL 3.340", maximum case length 2.500", MAP 53,000 cup.
The Hornady Handbook, Sixth Edition shows the following loads with their 129 grain bullets: 64.9 grains of H870 powder for a MV of 2800 fps, and a maximum load of 77.2 grains of H870 for a MV of 3200 fps. This is a fine ultra-long range load for all medium size big game animals.
Using the popular 140 grain Hornady bullets, 65.2 grains of H870 is good for a MV of 2600 fps, and a maximum charge of 77.3 grains of H870 gives a MV of 3100 fps.
The trajectory of a 140 grain spire point bullet at a MV of 3100 fps looks about like this: +2.5" at 100 yards, +2.3" at 200 yards, and -3" at 306 yards. 140 grains is probably the best all-around bullet weight for the .264 Magnum.
Hornady data also shows that the long 160 grain RN bullet can be driven to a MV of 2500 fps with 60.6 grains of H870 powder. A maximum load of 72.0 grains of H870 powder delives a MV of 2900 fps.
Hornady ballistics tables show that when zeroed at 200 yards the 160 grain RN at a MV of 2800 fps will hit +2.3" at 100 yards and -10.2" at 300 yards. This is not a long range bullet, but it has a SD of .328 and offers extreme penetration for use on heavy or dangerous game.
All of these Hornady loads were developed using Remington cases and Remington 9 1/2 primers. They were tested in a 24" rifle barrel.
Note: A full length article about the .264 Winchester Magnum can be found on the Rifle Cartridge Page.
Copyright 2005, 2012 by Chuck Hawks. All rights reserved.