When most people think of an Ackley Improved version of a cartridge, velocity increase seems to be the primary consideration. It is a definite result of the case shape change but in fact, there are other advantages to Mr. Ackley's design that to me at least equal if not outweigh improved velocity.

For starters, one of the main causes of bottleneck rifle case failure is case stretching. When a cartridge of that type is fired, its "funnel" shape created by the taper in the body and the sloping shoulder almost promotes brass flow toward the neck. That in turn thins the case just above the case head and the dreaded bright ring of death starts to appear followed soon afterward by case head separation. The AI's straighter body walls and flatter shoulder angle, as illustrated by the photo below of my handloads in standard .243WIN and Ackley Improved, resist brass flow which results in much longer case life.



Another very real improvement is in accuracy. As the above photo also shows, one way the shoulder angle is flattened is by lowering the neck-shoulder junction, which yields a longer neck, something benchrest shooters consider paramount to good accuracy. You can also see a dark ring just below the AI case's shoulder - that's where the original shoulder stopped.

I have two Ackley Improved rifles, a .243AI varmint rifle with a 27" stainless fluted McGowan barrel and a .280AI with a 25" stainless fluted McGowan sporter barrel, both built on blueprinted Remington Model 700 actions. The .280's is factory engraved and has a factory detachable box magazine.





I floated the .243's barrel in a Hogue Overmolded stock myself and it shoots tiny one-hole groups at 100 yards with the now-discontinued 65-grain Berger BT match bullets at an average MV of 3,939fps. The .280 is bolted into an unaltered Remington Model 700 factory laminated stock with zero bedding being done - the pressure tabs in the forend are even still there. It shoots Berger 140-grain VLDs into under .400" at an average MV of 3,099fps with a powder charge nowhere near maximum. Some day, I'll bed it better or at least float the barrel and I wouldn't be afraid to bet on seeing one-hole groups from it as well.

I enjoy my Ackley Improved cartridges and think my next one is going to be a 6.5/284AI or maybe I'll just have my .260REM converted.

Ed