Mostly Long Guns

During the 1930s, Charley O’Neil, Elmer Keith and Don Hopkins (O.K.H.) began designing a line of cartridges that were ahead of their time and filled specific sporting cartridge voids. For today’s discussion, the 285 O.K.H. is of special interest, as it is based on the 30-06 Springfield case but necked to accept 7mm caliber bullets. Records suggest that the shoulder angle remained the same as the 30-06, but chambers were throated to accept long, heavy-for-caliber bullets seated out or with the base of the bullet even with the bottom of the neck. Another interesting feature included a small tube that was installed inside the case and designed to carry the primer ignition energy to the front of the powder charge and burn it in reverse, which Elmer called a “Duplex load.” Keith loads used a special Western Tool and Copper Works 180-grain bullet that he also designed to achieve a high ballistic coefficient (BC). Keith reported impressive velocities, primarily with 175- to 180-grain bullets.

The inserted Duplex tube in the 285 O.K.H. case was reported to lower pressures and increase velocity. However, it was somewhat impractical for manufacturing or even handloading. Regardless, the more or less same wildcat cartridge eventually became known as the 7mm-06 but was void of the Duplex tube. In 1957, Remington introduced that wildcat as the 280 Remington, but it was based on the 30-03 case (about .046-inch longer than the 30-06) to prevent cartridges from chambering in a 270 Winchester. It was initially chambered in the pump-action Model 760, autoloading Model 740 and Models 721 and 725 bolt action rifles. It was intended to compete with the 270 Winchester; however, the 270 had a 32-year head start!

To make matters worse, the industry pressures for the 280 were established at 50,000 copper units of pressure (CUP), currently 60,000 psi, which is 5,000 psi less than the 270 Winchester. It has often been stated that this was due to the pump-action and autoloading rifles that the 280 was chambered in; however, that is not true. Remington chambered the same rifles in 270 with its higher pressures. Regardless, performance was left on the table, so to speak, and savvy handloaders can make notable ballistic improvements when compared to factory loads.

Despite offering greater versatility and being a truly excellent cartridge, the 280 never outsold the 270. In an effort to renew interest, in 1978, Remington renamed it the 7mm-06 Remington. Then, in 1979, Remington reintroduced it as the 7mm Express Remington, but that name caused considerable confusion with the 7mm Remington Magnum. In 1981, it was changed back to the 280 Remington. Regardless, it has proven to be a truly great cartridge in the field and on long-range targets, where it has won many open-class 1,000-yard matches.

P.O. Ackley, “the renowned” Utah-based gunsmith, created many wildcat cartridges, which were normally known as “Ackley Improved.” Most of his designs took an existing cartridge, such as the 280, moved the shoulder forward, changed the shoulder angle to 40 degrees and made other minor changes. In addition to Ackley cartridges being easy to fireform, his designs added powder capacity and velocity. The sharp shoulder angle increased in-chamber burn efficiency, reduced throat erosion, etc. Most Ackley Improved cartridges offered a notable velocity gain over the “parent” round. As such, they became very popular wildcats.

The 280 Ackley Improved (AI) was a truly standout wildcat. In fact, it was so good that sometime prior to 2006, it caught the attention of Bob Nosler, President and CEO of Nosler, Inc. The decision was made to introduce it to SAAMI and then offer it commercially in the Nosler Model 48 rifle and offer factory-loaded ammunition. After the approval process, it was formally introduced in 2008. Some important details of the industry-standardized cartridge include slightly less body taper than the original 280, a slightly shorter case and the pressures were increased by 5,000 psi to 65,000 psi.

In essence, a combination of a 5 percent powder capacity increase, a more efficient powder burn and higher pressures allow the 280 AI to perform very close to the 7mm Remington Magnum. In fact, from 24-inch barrels, most 140-, 150- and 160-grain bullets can usually be pushed to within 50 to 100 fps of 7mm Remington Magnum velocities. However, it reaches those velocities with around 5.0 to 8.5 grains less powder, with most bullets weighing between 140 and 175 grains. In addition to reduced throat erosion and longer barrel life, the muzzle report and recoil are notably less. The 280 AI has proven to give very low extreme spreads from shot to shot and outstanding accuracy, but we are getting ahead of ourselves.

Nosler Custom factory loads push several 140-grain bullets at 3,200 fps, 150-grain Accubond Long Range at 2,930 fps and the 160-grain Accubond Long Range or Partition at 2,950 fps from 24-inch barrels. In checking factory loads for velocity, consistency and accuracy, their extreme spreads are often between 5 and 20 fps for a five-shot string. At the same time, 100-yard groups usually hover under 3/4-inches from a Kimber Classic Custom 84L rifle with a relatively lightweight barrel.

As can be seen in the accompanying handloading table, the 280 AI thrives on powders with burn rates that usually fall between IMR-4350 and IMR-7828 with 140- through 162-grain bullets.

From shooter and hunter standpoints, the beltless 280 AI boasts smooth, reliable feeding in bolt action rifles, just like the proven 30-06. It usually offers two additional rounds in the magazine than the 7mm Remington Magnum or other comparatively fat rounds. The smaller diameter case allows it to be chambered in small ring actions such as the lightweight Kimber 84L. It is a highly versatile cartridge that is suitable for antelope, deer, elk, moose, black bear and most African plains game when mated with correct bullets. As indicated, it is a capable long-range round. In addition to Nosler offering guns, Savage, Browning, Weatherby and others produced rifles. In a very crowded field of excellent, completely modern sporting and hunting cartridges, the 280 AI is still a top-drawer choice due to its unusual blend of velocity, accuracy, efficiency, long barrel life and overall performance, but it also has a colorful history.