The .280 Remington Ackley Improved
By Chuck Hawks
The .280 Remington, based on a necked-down .30-06 case, is a fine all-around rifle cartridge in its own right. Parker O. Ackley "improved" the basic .280 by sharpening the shoulder angle to 40 degrees and reducing the body taper to create the .280 Ackley Improved wildcat.
The .280 Ackley Improved is among the most popular of all wildcat cartridges. It lies between the .280 Remington and the 7mm Remington Magnum in both recoil and performance. .280 Improved brass can be created by fire-forming standard .280 Remington cartridges in a .280 Improved rifle.
The approximate basic specifications of the .280 Improved are as follows: rim diameter .473", base diameter .470", shoulder diameter .450", neck diameter .315", case length 2.54", cartridge overall length 3.34". The .280 Imp. accepts standard 7mm (.284") bullets.
The 5th Edition of the Nosler Reloading Guide includes reloading data for the .280 Ackley Improved and the following loads are taken from that source. All of these loads used reformed Remington cases and Federal 210 primers and were tested in a 24" barrel.
A 140 grain Nosler bullet in front of 54.5 grains of IMR 4831 powder gave a MV of 2920 fps. The maximum load for that bullet weight is 58.5 grains of IMR 4831 for a MV of 3164 fps. IMR 4831 was the most accurate powder tested by the Nosler technicians with their 140 grain bullets.
A 160 grain Nosler bullet in front of 54.5 grains of AA3100 powder gave a MV of 2708 fps. The maximum load for that bullet weight is 58.5 grains of AA3100 for a MV of 2903 fps. AA3100 was the most accurate powder tested by the Nosler technicians with their 160 grain bullets.
The .280 Rem. Ackley Improved is a fine all-around cartridge for CXP2 and CXP3 game. It will do little that the standard .280 Remington will not do, but by the same token, the 7mm Remington Magnum will do little that cannot be done by the .280 Ackley Improved.
Copyright 2006, 2013 by Chuck Hawks. All rights reserved.