.250 Savage Ackley Improved

Loads for a Classic Cartridge

- Jim Matthews

The .250 Savage Ackley Improved rifle used in this test was a rebarreled Remington Model 700 short action featuring a sporter weight Shilen barrel. It has a 1:10 twist that stabilized even the 115-grain Berger.

It could easily be argued that the first “Creedmoor” cartridge distantly predates the current 6mm and 6.5mm versions that have become so wildly popular. The .250 Savage Ackley Improved (AI) might just as well be called the “6.35mm Creedmoor.”

There was a recent post on an online shooter’s site where someone asked what led to the explosion in popularity in the 6.5mm, especially the 6.5 Creedmoor. In some ways, it was driven by the same criteria that led to the development of the .250 AI by rifle fanatics of a different generation.

In both circumstances, the rounds were developed utilizing the highest and best technology available in their era. It is easy to understand why the 6.5mm (.264 inch) bullet was used for the first Creedmoor rounds of this generation: There were already long, heavy-for-caliber, high ballistic coefficient (BC) bullets and fast twist rifle barrels available in this caliber.

The .250 Ackley Improved (left) is shown next to its parent case. The improved version increases case capacity by about 14 percent by eliminating nearly all body taper and sharpening the shoulder to 40 degrees.