The .308 Winchester Ackley Improved is a cartridge based on the .308 Winchester, which has been improved upon in order to increase its performance. This improvement was designed by P.O. Ackley and included an increase in case capacity by necking up the existing .308 Winchester case as well as lengthening it slightly.The Ackley Improved version of the cartridge offers an average velocity of 3,000 fps and is more accurate than its predecessor due to improved harmonics and reduced wind drift. Long range shooters often prefer this variant as its higher velocities allow for flatter trajectories at extended distances which can result in more successful shots with fewer misses.
Caliber Statistics
Standard / Datasheet
Primer Size
Large Rifle (LR)
Max. Case Length
59 Grains of Water
Bullet / Barrel Diameter
0.308'' | 7.82 mm
Max. Case Length
2.014'' | 51.16 mm
Max. Cartridge Length / OAL
2.8'' | 71.12 mm
Max. Standardized Pressure:
60191 psi | 4150 bar
XXL ID
CID_403
- Bullet Weight (gr) ->0-5050-7575-100100-150150-200200-300>300
The following table indicates for this caliber and various bullet weight ranges (in grains) which powders are suitable (👍) and popular among our reloading community (👍👍). This might evolve over time as more community members share their loads and as we accumulate more calculations and tests with our balistics calculator.
Weight vs. Velocity - Suitable Bullets for this Caliber
You need to get an access license to view this chart. See an example with the following caliber: .22 Nosler
Barrel Length Variation vs. Velocity - by Bullet Weight
.308 Win. Ackley Improved load data available is with the following bullets:
(most popular first)
