The .28 Nosler is a shortened version of the 7mm Remington Ultra Mag. They share a maximum body diameter of 0.550 inch. Rebating the rim to 0.534 inch simplifies the production of rifle bolts since the rims of Holland & Holland-style belted magnums, such as the 7mm Remington and .300 Winchester, are the same diameter. Whereas the 7mm RUM case measures 2.387 inches long from head to body-shoulder juncture, that dimension on the .28 Nosler case is 2.166 inches.
The dimension at that point on the Nosler case is 0.002 inch larger and that reduces its body taper by just a tad. Maximum case lengths are 2.850 and 2.590 inches respectively. Shoulder angles are 30 degrees for the Remington cartridge and a slightly sharper 35 degrees for the Nosler. Due to its greater length, the Remington case is about 25 percent more capacious than the Nosler case.
The .28 Nosler case can be formed by running 7mm RUM or .300 RUM cases through a .28 Nosler full-length resizing die with its expander/decap assembly removed and then trimming to the proper length. But despite the best of efforts, case loss will be high due to wrinkling.
A case-forming die is available from Redding, and while I have not tried it, another Redding die on my shelf forms the 6.5 Remington Magnum and .350 Remington Magnum cases from the longer 7mm Remington Magnum case. Case loss is zero with it.
280 Ackley Improved Ammo
P.O. Ackley and Fred Huntington developed the 280 Ackley Improved. Previously, it was known by a variety of names like the 280 Rem. Ackley Improved by 40 degrees. Fred Huntington is the founder of RCBS, and he developed the .280 RCBS by blowing the body taper of the .280 Remington. He also changed the shoulder angle to 35 degrees.
On the other hand, P.O. Ackley, a famous gunsmith, and ballistician changed the shoulder to 40 degrees and lent his surname, which is how the 208 Ackley Improved Ammo was born. It was standardized by Nosler and accepted by SAAMI in 2008. Like most of the Ackley improved cartridges, the .280 Ackley Improved ammo provides a definite velocity advantage.
The additional case capacity it offers has its advantages but doesn’t change the laws of physics. The 280 Ackley Improved Ammo will offer 100 extra fps with an equal barrel length than the 280 Remington with a 140-grain bullet. The real advantage of the 280 Ackley Improved Ammo lies in its versatility.
When you’re chasing antelopes or predators, 120-grain bullets are pretty effective for a clean kill at nearly 3,400 feet per second. It only drops five inches at 300 yards. You can also use the 280 Ackley Improved Ammo for elk hunting. A 160-grain bullet screams along at 3000 fps, while a 175-grain bullet also crosses the 2800 fps mark.
The .280 Ackley Improved Ammo also offers increased magazine capacity. As a result, it is suitable for several hunting games and doesn’t give you the recoil of a magnum round. It also provides heavier bullet options and a flatter trajectory, which makes it ideal for big games.
