You do not have to be around shooting for very long before you come across the name Parker O Ackley. He is remembered mostly for his lengthy list of ‘improved’ cartridge cases.
Ackley’s designs blew out the case shoulders of factory cases, shortened the neck a bit and steepened the shoulder angle to some 40 degrees.
The result was a modest increase in powder capacity and a reduction in case lengthening.
Parker had his detractors but his improved cartridges were just that.
One case I used stood out to be improved — the .243 Winchester, a flexible case I had loaded for some time
My Ruger 77 Varmint rifle’s barrel was worn out so I had rebarreled to .243AI and ordered a set of straight-line dies.
The next issue was projectiles. Initially, I concentrated on the heavier ones, in the 100-115gn range, both a flat base and a boat tail, in protector point configuration.
I had several conversations with Brisbane custom bullet maker Gary Little and soon had 103, 107 and 115gn projectiles to load develop.
I fire-formed standard .243 cases, though there was no requirement to do so because Ackley designed his improved cases to allow the parent case to be fired in the reamed rifle chamber.
For the 103 and 107gn projectiles, several powder and primer combinations resulted in velocities in the 3000-3100fps range with sub-MOA three-shot groups.
The best was 46gn of RE-26 producing 3080fps and consistent groups of 0.44 inches, all very straightforward until powder stocks dried up at the time. Possibly the 103gn rounds were a fraction better than the 107s.
For the 115gn projectiles, ADI AR2213SC proved to be the fastest powder at 2900fps with groups averaging 0.05 inches.
AR2217 was close to AR2213SC, with AR2225 the slowest of the three but still accurate.
Cases were easy to work with and all load development was straightforward
For lighter bullets I looked at Nosler Ballistic Tips. Initial loads showed a velocity of 3860fps and accuracy in the 0.60 range, but supply became a problem.
Gary Little came up with 60 and 66gn cone-headed projectiles. I loaded the lighter 60gn versions in a standard .243 Winchester cartridge.
For the 66gn model, conventional load development using ADI 8208 powder and CCI BR2 primers produced a load of 41.5gn at 3559fps with groups averaging .95”.
The other projectile of interest was a bit different — an RWS 96gn cone-point partition type projectile. Coupled with the accuracy of the .243 Ackley Improved cartridge, I thought it might be a good short-range pig round.
Development produced a load of 41.5gn of BM8208 at some 3030fps and overall accuracy just a whisker under one inch. They should be ideal out to about 250 metres or so.
Having sorted out the projectiles and load development, the rifle has some serious work to do. I am sure it is up to the task.