I consider Ackley an attention seeking snake oil salesman.
Post WW2 Ackley is out there claiming that he has created a series of cartridges which are vastly superior in all respects to factory cartridges, all by the simple act of blowing out the shoulder to 40 degrees and straightening the case walls. This did increase powder capacity, a trifle in most cartridges. At the time there were a number of Wildcatters, each claiming that with a simple trick, their cartridge design was the best, the most, fabulous of them all. Most of the tricks involved increased powder supply, reduced caliber, and variations in shoulders. The most farcical claim Ackley made was that his cartridges could run at much higher pressures than standard cartridges because the straight taper of the case
“reduced bolt thrust”. Therefore, the shooter/reloader could push the bullet faster than standard cartridges.
I am certain that the old school Military Arsenal guys at the American Rifleman were upset by Ackley’s claims that he had improved the 30-06 above and beyond anything the US Army Ordnance Department could do. The 30-06 was a beloved cartridge, had been successfully used in two World Wars and a number of bush wars, and the fact some machinist was flapping his jaws over the vast improvements he had made to an Army Ordnance Department cartridge was no doubt galling to the retired Ordnance Department experts on the NRA Staff.
Unlike Ackley, the American Rifleman staff decided to spend some money testing Ackley’s claims. The Dec 1953 article
How Improved is it? was the result.
The American Rifleman staff contracted with HP While Laboratories to conduct pressure and velocity tests of a 30-06 and a 30-06 AI Cartridge. They conducted pressure tests at standard pressures and measured the pressure averages for ten data points, and the velocity averages for ten data points. They also conducted one over load test, that is test above industry standard standards. They analyzed the standard cartridge and the AI cartridge for pressure sensitivity at standard pressures and overload pressures. Obviously Ackley had been making claims about his case configuration giving less pressure for more velocity, providing more consistent velocities, and probably a bunch more
“you can have your cake and eat it too” sort of arguments.. It is instructive to read within the 1953 American Rifleman article that Ackley, and that generation of Wildcatters have very little velocity data and absolutely no pressure data. These guys were publishing reams of pseudo science within the popular print media, all of which was accepted, but nothing in terms of real data and objective test results. The fact that the American’s Gunwriters still adhere to Ackleyism is a sad reflection on the critical thinking of that segment of the shooting community. Some of these early wild catters, Ackley particularly, had gained a celebrity status in the media. Ackley was a regular contributor to magazine articles and made a lot of money and had a brand recognition. Being a celebrity adds great credibility in the minds of many. The general population accepts that Celebrities have a greater insight into all things, animal or mineral, than non celebrities.
The NRA article had real test data, something of which if you notice, Ackley did not, and the article concluded that the 30-06 Ackley Improved had not changed the laws of physics, nor were the claims by the fan base substantiated by their results.
The results of these tests, as shown in table 2, failed to reveal any marked superiority of the improved cases over the standard version.
a higher velocity can be reached at a safe chamber pressure with the standard version of the 30-06 than the experimenter can attain with the Ackley Improved 30-06.
in all other respect, in so far as we can discover, the Ackley Improved 30-06 can not do anything that the normal old fashioned 30-06 can do just as well or better
The old line Army Ordnance writers of the NRA bitch slapped P.O. Ackley in print, but charlatans tend to be persistent and shameless, and I have seen nothing in Ackley's books or articles of the 1950's that anything the NRA did altered his claims. In the first issue of Handloader, Vol 1 1966, Ackley writes an article titled
“Wildcat Pressures” . It is worth looking at this article for the important point that Ackley set out to prove was that shoulder angle/shape meant nothing for velocity. Decades later people have probably forgotten the other Wildcatter’s who were promoting their designs, but one was Roy Weatherby. Roy Weatherby created a
double venturi shoulder, and he claimed he got his massive velocities increases at a safe pressure, all due to his special shoulder design. This of course conflicted with Ackley’s claims that his design was better. Ackley claimed that the straight taper of his cartridges reduced bolt thrust, and therefore, it was safe to increase pressure, and velocity, with AI cartridges. Both of these characters were fooling the public, and may have been fooling themselves, never know, but the velocity increases both got were due to two factors: increased powder volume and vastly increased pressures. Their typical cartridge ran at or above factory proof pressures for the standard cartridge.
Ackley’s whole article is a thinly veiled debunking of other Wildcatter’s designs and the punch line is:
What we have found is that some loads published for wildcat cartridges cannot be considered safe. It shows that you cannot change the shape of the case and the shoulder angle and revolutionize the industry.
A few interesting data points are that Ackley claims the most common load for the 30-06 Ackley improved, a load of 60 grains IMR 4350 with a 180 grain bullet, gave a pressure of 62,000 psia, and a load of 61 grains (still common) gave a pressure of 66,000 psia. Given that Ackley measured a factory 30-06 at 54,000 psia, it is no wonder that Ackley Improved cartridge move faster. Any fool can push a bullet faster, just increase the pressure. At some point the cartridge pressure exceeds the structural capability of the firearm, and all sorts of high velocity projectiles will be flying. Whoopee!
But what about the bolt thrust claims?, Ackley insisted that his cartridges reduced bolt thrust, therefore it was safe to run his cartridges hot. Extraordinary claims require extraordinary evidence, but snake oil salesman make lots of unverifiable claims. What I found real interesting in the article is the picture of
Ackley’s pressure, velocity and bolt thrust equipment
I for one do not believe in one moment that straightening a cartridge case reduces bolt thrust, because, straightening the case does not thicken the sidewalls. If the case has to carry load, and if you want to case to carry load (a bad idea in all physical universes), than the physical case, the sidewalls and the case head, will be carrying that load. Most of the case is a tube, a thin walled tube. The case head is the thickest part, and that makes the case a pressure vessel. Even though you cannot crush a case in your hand, it is really not very strong. At the operating pressures of a small arm, the cartridge case is the weakest piece in the whole system. When a case blows, bad things happen to a firearm. A thicker case can carry more load than a thinner case but nothing Ackley did made the case walls thicker. He simply took factory made cartridges and blew them out and straightened the sidewalls. Also, reducing bolt thrust does not make the load on the chamber go away. Increasing pressure increases the stress on the case, action, chamber and barrel. Ackley did a version of three card Monte, where he fooled people into thinking that load went away, or he diverted it, none of which he did. And he did not transfer it anywhere, and if it had been transferred anywhere, it would have increased the stress on the other components in the system. What Ackley did with his cartridge designs was to add a little more powder space and a lot more pressure.
And he had a bolt thrust measuring device. Just where is the data? I am of the opinion that Ackley did have the data, did not publish it, because the data would have shown that his fundamental claim to fame was false. I am confident the data would have shown that his case design did not reduce bolt thrust because his cases were simply factory cases blown out and straightened. Instead of publishing that data, he is rubbishing the claims of competing Wildcat designs, but not his own.
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