The .244 Ackley Improved

By Chuck Hawks

P.O. Ackley, one of the most famous of all wildcatters, practically made a career of "improving" various standard rifle cartridges. The improvement usually took the form of reduced body taper, a sharper shoulder, and a shorter neck to increase powder capacity and thus performance. Improved cartridge brass is created by simply firing ("blowing-out") standard cartridges in an improved chamber. This is exactly the course Ackley followed when he improved the .244 (6mm Remington) case.

The 6mm Remington is an exceptionally well balanced rifle cartridge. In fact, the later .243 WSSM does nothing more than equal 6mm Remington performance in a shorter (but fatter) case. So the .244 Ackley Improved is a standard cartridge that outperforms not only its 6mm Remington parent, but also Winchester's new .243 "Magnum."

The basic specifications of the .244 Ackley Improved include a rim diameter of .472", a base diameter of .470", a shoulder diameter of .457", a case length of 2.23" and an overall cartridge length of 2.80". Bullet size is .243", like any other standard 6mm cartridge.

Because there are no SAAMI pressure specifications for improved cartridges, and wildcatters tend to be hot-rodders at heart, the 9th Edition of Cartridges of the World lists QuickLoad data for the .244 Ackley Improved based on moly-coated bullets fired from a 26" barrel at a MAP of 65,000 psi!

Given those parameters, the .244 Ackley Improved is alleged to be able to drive a 95 grain Nosler Partition bullet at a MV of 3546 fps with 56.5 grains of Viht. N560 powder. The same source lists a MV of 3399 fps for a 105 grain Speer bullet in front of 54.5 grains of Viht. N560.

If true, this would mean that the .244 Ackley easily outperforms the 6mm-284, 6mm-06, and even the .240 Weatherby Magnum! None of which, of course, is possible if all are loaded to the same MAP. It would be more realistic to shoot for a maximum MV of about 3200 fps with standard (not moly-coated) 95 grain bullets and 3100 fps with 105 grain bullets, which is treading very closely on the heels of the 6mm-284.

The 6mm Ackley Improved is a fine cartridge, one of the best and most popular wildcats. With performance so similar to that of the 6mm-284 and the ability to shoot standard 6mm Remington factory loads in a pinch, it is probably a better deal than the 6mm-284. Reloading dies are available from RCBS.

Back to Wildcat Cartridges

Copyright 2005, 2013 by Chuck Hawks. All rights reserved.