The .256 Winchester Magnum
By Chuck Hawks
The .256 Magnum is a varmint and predator cartridge introduced by Winchester in 1960. In 1961 Ruger brought out the Hawkeye single shot pistol for the .256 Magnum. The next year (1962) Marlin chambered their Model 62 Levermatic rifle for the new Winchester cartridge. These were the two principle firearms chambered for the .256 Win. Mag.
The Ruger Hawkeye was an unusual single shot pistol based on the Peacemaker style grip frame of the Ruger single action revolvers. In place of the cylinder was a unique pivoting breech block. Unfortunately, the Hawkeye's Peacemaker grip and rather long, heavy hammer blow were not to the liking of varmint pistol fans. I believe that the Hawkeye was the least commercially successful of all Ruger pistol designs. Today, most Hawkeye pistols are in the hands of Ruger collectors.
The Marlin Model 62 was a modern, sleek, hammerless, lever action rifle that was probably the best of the firearms chambered for the .256 Mag. It came with a 24 inch barrel with a 1 in 14 inch twist; blued steel barreled action, and a walnut stock. It was also offered in .22 WMR caliber. Unfortunately, it did not sell very well and the Model 62 was discontinued after a relatively short production life.
In addition, the Universal Firearms version of the semi-auto U.S. M1 Carbine was also briefly chambered for the .256 Mag. Thompson/Center turned out a few Contender single shot pistols in .256, and at one time the Merrill Single Shot pistol was also available in .256. I know of no other production guns chambered for the cartridge.
The .256 Magnum cartridge is based on the .357 Magnum revolver case necked-down to accept .257 inch bullets. It is a rimmed, bottleneck case with a .440 inch rim diameter, a .378 inch base diameter, and a 25 degree shoulder. The case length is 1.281 inches, and the overall cartridge length is 1.59 inches.
Because the case capacity is relatively small, lighter bullets are preferable. The usual bullet weights are 60 and 75 grains, although 87 grain bullets intended for the .250-3000 and .257 Roberts can also be used.
Winchester offered factory loaded .256 Magnum ammunition (and brass to reloaders) into the beginning of the 1990's. Winchester .256 factory loads used a 60 grain Open Point Expanding bullet at a MV of 2760 fps and ME of 1015 ft. lbs. from a 24 inch rifle barrel. That is about 500 fps faster than Winchester factory loads for the old .25-20 cartridge. At 200 yards the velocity was 1542 fps and the remaining energy was 317 ft. lbs.
From an 8.5 inch pistol barrel the 60 grain .256 Winchester factory load was advertised as having a MV of 2350 fps and ME of 735 fps. This was 250 fps faster and nearly twice as powerful as the .22 Jet, a varmint cartridge for revolvers that was also based on a necked-down .357 Magnum case.
It is my recollection that attempts were made to adapt the .256 Magnum to revolvers, but that its sharp shouldered bottleneck case would set back when fired, tying up the cylinder. This problem also plagued the .22 Jet, which was designed with a long, sloping shoulder to minimize the effect.
According to data from the fifth edition of the Hornady Handbook of Cartridge Reloading handloaders with a .256 rifle can approximately duplicate the Winchester factory load using the Hornady 60 grain Flat Point bullet in front of 15.5 grains of H4227 powder for a MV of 2700 fps. The trajectory of that load looks like this: +2.3 inches at 50 yards, +4.4 inches at 100 yards, 0 at 200 yards, and -26.2 inches at 300 yards.
A better option for handloaders would be the 75 grain Hornady V-Max bullet in front of 14.2 grains of H4227 powder for a MV of 2400 fps and ME of 959 ft. lbs. The 200 yard figures are 1855 fps and 573 ft. lbs. The trajectory of that load looks like this: +1.7 inch at 50 yards, +3.2 inches at 100 yards, 0 at 200 yards, and -13.3 inches at 300 yards. This is a deadly 200 yard varmint load, but under no circumstances should it be used on deer or any other North American medium size big game animal.
Alternatively, and more appropriately for use on varmints and small predators, such a load could be zeroed so that the bullet hit about 2 inches high at 100 yards and about 2 inches low at 200 yards. These Hornady loads all used Winchester brass and WSR primers and were chronographed from the 24 inch barrel of a Marlin Model 62 rifle.
The recoil of the .256 Mag. with any of these loads is minimal. According to the "Rifle Recoil Table" a 7.5 pound rifle shooting a 75 grain bullet at a MV of 2400 fps generates only 2.4 ft. lbs. of recoil energy.
Reloaders with a Ruger Hawkeye or other single shot pistol can achieve a MV of 2300 fps with a 60 grain bullet behind 16.0 grains of H4227 powder. Or, with a 75 grain bullet, the Hornady Handbook shows that 13.2 grains of H4227 powder can achieve a MV of 2000 fps. The Hornady technicians used Winchester cases and WSR primers for these loads, which were chronographed in the 8.5 inch barrel of a Ruger Hawkeye pistol.
The .256 Winchester Magnum is an interesting cartridge that simply never caught on. It is a perfectly satisfactory 200 yard varmint and small predator cartridge. It can outperform the old .25-20 and similar cartridges, as well as the .22 Hornet and .218 Bee. But the .256 cannot match the Remington .221 Fireball, another combination pistol and rifle varmint cartridge that was introduced about the same time.
Copyright 2003, 2012 by Chuck Hawks. All rights reserved.