As long as shooters have been squeezing triggers there has been a desire to achieve a higher level of performance from their firearms. After World War Two and especially during the 1960s there was a great deal of work devoted to modifying cartridges largely in an effort to increase velocities.
During that time many wildcat cartridges were developed, a few of which ultimately wound up being ‘legitimised’ by the ammo and firearms companies who adopted those designs for production. However, many other models didn’t achieve that same level of accreditation, but are in their own rights no less impressive.
P.O. Ackley’s improved designs
During that heyday of wildcatting the name P.O. Ackley became almost synonymous with the concept of improved cartridge designs. To create these new items it became necessary to fire the production cartridges inside the chamber of a rifle which had been dimensionally modified. Mostly those dimensional changes included straighter case walls and a sharper shoulder angle which resulted in increasing the powder capacity of the cartridge. Once that had been accomplished those cases could be handloaded using a set of the dies possessing the new Ackley Improved dimensions.
Some people believe Ackley’s most successful modification is the .280 Ackley Improved. They base that belief largely on the fact Nosler eventually decided to take its dimensions to SAAMI (Sporting Arms and Ammunition Manufacturers’ Institute) for testing, documentation and approval so it could be marketed as a true factory round.
But while the .280 Ackley Improved is certainly a good cartridge, there are many others that are equally creditable and noteworthy.
.30-06 Ackley Improved
I am often amazed at how prolific Ackley really was, redesigning and improving the factory produced cartridges. Almost any cartridge of the Ackley era seems to have an Ackley Improved version counterpart associated with it, but one of my own personal favourites is the .30-06 Ackley Improved.
This is a very efficient round which possesses about nine per cent greater powder capacity over that of the standard .30-06. That additional powder capacity is capable of generating an increase in muzzle velocity of about 150fps. Even though that speed falls a little short of the performance of most .30 calibre Magnums, it comes reasonably close to many of them and certainly is a substantial improvement to the standard .30-06 Springfield.
It is true that many bolt-action .30-06 chambered rifles could be rechambered to .300 Winchester Magnum, which would produce slightly higher velocities. I’ve owned a couple of rifles which have been coveted in this manner and still possess one. But unlike the conversion to .30-06 Ackley Improved, which only usually requires the rechambering of the rifle chamber, there is additional work associated with making the jump to the .300 Win. Mag. It would also be necessary for a modification of the bolt face in order to accept the belted Magnum head.
And in at least a few examples the bolt face may not be large enough to handle that modification. There is also a chance of feeding problems occurring, which don’t seem to be as prevalent with the .30-06 Ackley Improved. Another downside to the .300 Win. Mag is that some shooters do not like its short neck, believing it is not capable of holding the bullets as securely as they would prefer. While I don’t personally support those concerns, the much longer neck of the .30-06 Ackley Improved is certainly an asset worthy of consideration.
The simple process of conversion
One of the biggest advantages in converting a rifle over to an improved design is the ease at which it can be accomplished. As mentioned earlier, all that is usually necessary is to have a gunsmith cut the chamber to the new specifications.
The bore diameter of the rifle would stay the same so there are no worries associated with having to replace the barrel. The cartridge case head also remains the same, so again, no worries there either. However, you would have to purchase a set of reloading dies that possess the new dimensions, but making the cartridges cases is as easy as firing the standard calibre cartridges in the new chamber in order to fire-form them then running them through your normal reloading processes.
Unlike most other wildcat designs, in most if not all instances, a rifle possessing an improved chamber can safely fire either the standard production calibre cartridges, or the new improved shells.
Did the Weatherby designs influence Ackley?
I’m not sure how much of an influence the Weatherby line of cartridges had on Ackley’s thinking, but both include similarly straight case walls and sharp shoulder angles, frequently about 40 degrees. While Weatherby obviously was and still is today heavily vested in large case capacities, Ackley seemed to prefer more moderate increases, which results in making the rounds considerably more efficient, but still capable of getting the job done.
Other noteworthy wildcats
In addition to the improved version wildcats, I would be remiss if I didn’t talk about the other style of wildcats. While a conversion to one of these will likely be more costly, they are nevertheless worth consideration.
Prior to Remington finally coming out with their .17 Fireball, I had a custom rifle built in a similar but wildcat version called the .17 Mach IV. To make the brass for this rifle you begin with new .221 Remington Fireball cartridge cases. Those must then undergo a two-step case forming process in order to squeeze the necks down from .22 to .17 calibre.
That takes the cases down close enough to the dimensions of the new chamber for them to be run through the normal resizing die prior to loading and fire-forming. The result in a great cartridge which is best suited for small to middle-sized varmints or the same size of game species.
Another similar and great wildcat, the .20 VarTarg, also utilises the case of the .221 Remington Fireball, but is loaded with the slightly larger .20 calibre bullet.
The basis behind many wildcat cartridges is a desire to increase velocities, but in a few instances there have been other concerns at work. One classic example lies in the .338-06 wildcat, which sacrifices speed for the sake of shooting a larger diameter and heavier bullet. In this case the standard .30-06’s neck is enlarged from .308 to .338. The straighter walls and sharper shoulder of the new case results in a slight increase in powder capacity which helps to move the heavier weight bullets, like the 225 and 250-grainers, out of the barrel still at a reasonable speed.
My personal experience on the .338-06 came from a hunting acquaintance living in an area where his shots at bears and deer seldom exceed 100 yards. In this case the hunter wasn’t so concerned with the longer range trajectory drop; he was looking for the benefits associated with a higher level of bullet energy.
I was honoured a while back to be a part of a development and testing project involving a series of new wildcat cartridges earmarked as the Garin SureStrike System. This unique venture involved the necking down of .30 calibre Carbine cases to accept an array of bullet diameters, which included: .17, .20, .22, .25 and .30 calibres. Due to my own personal time constraints I was only available to do the initial loading and testing of the three smallest calibres, but was able to develop the first of the loading data. Those cartridges were developed by a man named Paul Garin who now operates a website supplying virtually everything needed for these wildcats. On that site you can purchase the formed cartridge cases, reloading dies, chamber reamers, bullets and even chambered rifles in any of those five calibres. That website is: surestrikesystem.com
A few wildcat points to consider
● Sometimes when substantially squeezing down the neck diameter of a cartridge case it can increase the thickness of the brass to a point that it will be necessary to reduce that thickness. For an example a step down from say .308 to .270 may not add enough thickness to worry about, but if you are thinking of squeezing down a .338 sized neck to .243 or smaller, you will likely need to turn that thickness down.
● When squeezing down neck diameters it may require the use of forming dies and when major changes are necessary it might need to be done incrementally.
● Remember, wildcat cartridges will always show the identification of the parent case. Because of this, precautions are necessary to ensure those cartridges do not become mixed up with other ammo.
● On occasions it will take some digging to locate wildcat loading data. I have frequently found the older reloading manuals to be useful and the internet to be great source as well. But while the internet can be helpful in this endeavour, you must be careful to ensure that it comes from credible and reliable sources. Also, P.O. Ackley’s own book Handbook for Shooters & Reloaders Volume 1 is a great base for handloading data and also background information on his many wildcat cartridges.
● If you do decide to take a walk on the wildcat side, you will need a set of reloading dies and in some cases forming dies. While many handloading companies carry wildcat dies, Redding possibly has the largest selection. Their website can be found at: redding-reloading.com
The way I see it
Being a person looking to make whatever I use a bit better, I have always been drawn to wildcat cartridges. Just because the manufacturers choose to ignore the benefits associated with a higher degree of performance, doesn’t mean you have to.
If you choose to move into the area of wildcatting you can be assured it will cost you more money to do so than simply shooting a production calibre, but for those of us that have crossed those lines, the benefits and rewards in my opinion outweigh the expenses.