what is Ackley Improved?
- Thread starter upstate81
- Start date
warbirdlover
New member
He changed the cartridge case shoulder angles and basically designed a new round in which the case held more powder and yielded a higher velocity then the original (improved). RCBS has some "improved" rounds also. A good example is the .257 Roberts which has the two "improvements" (RCBS and Ackley). If you go to these you'll have to make your own cases (fire forming), buy the special reloading dies and handload.
P. O. Ackley : http://en.wikipedia.org/wiki/P.O._Ackley
warbirdlover
New member
Only if you like to shoot something rare that not many others have and you can appear to be a real knowledgeable gun nut. 
It's not too expensive to rent a reamer and change the rifle chamber, but I chose to not do it to a .22-250 Rem that shot too well to take a chance of screwing it up. The increased velocity and reduction in case stretching afforded by the Ackley version may be worth it to some folks, but not to me.
The 1/14 twist of the Remington rifling made it unfeasible to use heavier bullets than 55 grains, but in a rifle with a faster twist, the ability to shoot 70 grain bullets as an Ackley Improved might be worthwhile.
NOTE: I just rebarreled my (1983 vintage) 700 ADL to .243 Win...much more expensive than rechambering, but it's now a better caliber for larger varmints and a decent deer cartridge for my 4 grandsons to hunt with. I could have bought a new rifle for what the work cost me, but the rifle holds great memories and IMHO, better finished than new ones. Trading that one wasn't a good option, but I highly recommend it, if a person isn't attached to a particular rifle.
The 1/14 twist of the Remington rifling made it unfeasible to use heavier bullets than 55 grains, but in a rifle with a faster twist, the ability to shoot 70 grain bullets as an Ackley Improved might be worthwhile.
NOTE: I just rebarreled my (1983 vintage) 700 ADL to .243 Win...much more expensive than rechambering, but it's now a better caliber for larger varmints and a decent deer cartridge for my 4 grandsons to hunt with. I could have bought a new rifle for what the work cost me, but the rifle holds great memories and IMHO, better finished than new ones. Trading that one wasn't a good option, but I highly recommend it, if a person isn't attached to a particular rifle.
upstate81, I've always started with a new barrel for the Ackley's so never had any higher cost than I would if I it was chamber for a standard caliber provide gunsmith had the AI reamer.
If you cut a new chamber using existing barrel those cost vary and you have to buy new dies.
Outside of using little more powder the cost isn't really that much more than loading for the parent case. If you look at the 223AI very small case capacity 1/2 gr is big deal in working up load vs something like the 30-06AI.
I was lucky shot almost 15yrs before got my 1st AI and got help from some friends shooting the AI.
If you cut a new chamber using existing barrel those cost vary and you have to buy new dies.
Outside of using little more powder the cost isn't really that much more than loading for the parent case. If you look at the 223AI very small case capacity 1/2 gr is big deal in working up load vs something like the 30-06AI.
I was lucky shot almost 15yrs before got my 1st AI and got help from some friends shooting the AI.
P.O. Ackley was one of the leading gunsmiths of his generation. He did extensive testing of rifles and cartridges and wrote a couple of books about it that have become kind of gospel for generations.
One of his most famous and lasting things was "improving" various cartridges. THis usually involved a chamber cut to his specs which had a sharper shoulder (and sometimes moved a bit forward) which meant that formed brass could hold a few grains more powder than the "standard" round.
A little more powder meant a little more velocity, and a little flatter trajectory, over the standard factory round's performance. For some people this was enough to justify the expense of special dies, rechambering a rifle, etc. For others, not so much.
Some rounds get a pretty good boost in performance from Ackley Improvement. Others, not so much.
One advantage to all the Ackley Improved rounds (as far as I know) is that you can still fire standard ammo. Cases get fireformed to the new chamber dimensions in the process, although its preferred to fireform the brass using speical light loads intended for just that purpose.
So, if you have an Ackley Improved rifle, and you lose your custom made (handloaded) ammo, you could still get some regular stuff and hunt with it, in a pinch.
One of his most famous and lasting things was "improving" various cartridges. THis usually involved a chamber cut to his specs which had a sharper shoulder (and sometimes moved a bit forward) which meant that formed brass could hold a few grains more powder than the "standard" round.
A little more powder meant a little more velocity, and a little flatter trajectory, over the standard factory round's performance. For some people this was enough to justify the expense of special dies, rechambering a rifle, etc. For others, not so much.
Some rounds get a pretty good boost in performance from Ackley Improvement. Others, not so much.
One advantage to all the Ackley Improved rounds (as far as I know) is that you can still fire standard ammo. Cases get fireformed to the new chamber dimensions in the process, although its preferred to fireform the brass using speical light loads intended for just that purpose.
So, if you have an Ackley Improved rifle, and you lose your custom made (handloaded) ammo, you could still get some regular stuff and hunt with it, in a pinch.
Probably the most practical of the Ackley Improved cartridges is the .35 Whelen Ackley Improved. The basic .35 Whelen retains the 17 degree, 30 minute slope of the parent case (.30-06), but necking the parent up leaves precious little shoulder for headspacing purposes. There, the Ackley Improved version would be a better choice since the 40 degree slope of the shoulder would make headspacing of a chambered round much more positive.
Back in the 50's when PO Ackley came up with his wildcats they were a great improvement, compaired to some magnums, they burnt about 5% more powder and about 20% increase in velocity, where a magnum does juat about the opposite from the parent cartridge. But now a days in a given caliber there are so many choices that you do not need to do an improved unless you just want to be a gun loonie. For instance a 257Roberts into the 257 AI is about the same as the 25-06.
Bob
Bob
LOVE the .30-06 Ackley Improved. Think of it as the .308 Magnum! No need for those newer shoulder slamming, retina shaking, things. Yes, you'll reload your own. Cheap to do as the cases are common ones! As said, you fire-form them. And, in a pinch you can STILL fire an off-the-shelf .30-06 (obviously) factory load in it. Ackley's are generally about 10% more powerful than the standard cartridge it is based on.
My late father was a friend and fan of Parker Ackley. I have two of his rifles that Ackley himself 'Improved' - one is a Marhoff drilling with the rifle barrel chambered for .22 Savage High Power AI. It shoots a 70gr, .228 dia bullet at about the same velocity that a 22-250 shoots a 55gr. These bullets are hard to find and I have a stash of Speer hollowpoints from the '50s that I load and shoot sparingly. I have shot a few whitetails with this gun and it drops them right now with a boiler works shot. It absolutely pulverizes coyotes.
The other rifle is a single shot '98 Mauser chambered for 31-40 Krag AI. It's thirty one-forty because it was originally chambered for 8.15x46R which has a groove diameter of .315. I squish .323 (8mm) bullets down to .315 in a swage die, and I also shoot regular .312 (.303 Enfield) bullets which actually shoot quite well out to 300 yards considering they are a little under bore size.
The reason the old man had Ackley chamber it for his 30-40 Krag AI is because the rifle action required a rimmed cartridge. I load 52gr of H380 behind a 174gr Hornady RN and get what amounts to a 30-06. This load is actually a little light as the cartridge is capable of near .300H&H mag velocities using 4350 or 4831, but in an 8lb sporter the '06 equivelent load is more comfortable to shoot and is capable of killing anything in Idaho I want to shoot.
I guess all this qualifies me as a gun looney, huh?
George
The other rifle is a single shot '98 Mauser chambered for 31-40 Krag AI. It's thirty one-forty because it was originally chambered for 8.15x46R which has a groove diameter of .315. I squish .323 (8mm) bullets down to .315 in a swage die, and I also shoot regular .312 (.303 Enfield) bullets which actually shoot quite well out to 300 yards considering they are a little under bore size.
The reason the old man had Ackley chamber it for his 30-40 Krag AI is because the rifle action required a rimmed cartridge. I load 52gr of H380 behind a 174gr Hornady RN and get what amounts to a 30-06. This load is actually a little light as the cartridge is capable of near .300H&H mag velocities using 4350 or 4831, but in an 8lb sporter the '06 equivelent load is more comfortable to shoot and is capable of killing anything in Idaho I want to shoot.
I guess all this qualifies me as a gun looney, huh?
George
There are different degrees of ackley improved cartridges. The most common one you will notice is the fire formed 40 degree shoulder. What you would do in the case of you wanting an ackley is let your gunsmith ream your barrel to ackley dimensions for a given cartridge. Then you would simply load regular loads, say .260 for example. Fire them and they will fireform to those dimensions, thus giving your "ackley improved" case. Thus in turn you would just continue there to resizing them and so on. Attributes of the AI cartridges is much less trimming if any at all (i can't remember on that part) and depending on the cartridge in some cases up to 10% or more performance over the standard. Oh and lastly it looks down right gorgeous.
The 1889 7.65x53mm case head when built with a large Boxer primer will take about 67,000 psi in handloads for a particular rifle, and have long brass life, and not get loose primer pockets quickly.
If you load 257 Roberts loads from a load book.
If you work up 257 Roberts Ackley Improved to the threshold of loose primer pockets, and then back off a 4% powder charge safety margin.
Then you will see a 20% increase in velocity for the Ackley improved.
But if you worked up the non Ackley cartridge with the same process, the difference between cartridges would be more like 2% velocity improvement.
If you load 257 Roberts loads from a load book.
If you work up 257 Roberts Ackley Improved to the threshold of loose primer pockets, and then back off a 4% powder charge safety margin.
Then you will see a 20% increase in velocity for the Ackley improved.
But if you worked up the non Ackley cartridge with the same process, the difference between cartridges would be more like 2% velocity improvement.
warbirdlover
New member
All I know is my neighbor (20 years ago) who was a gunsmith built the most beautiful Ruger #1 up (custom super $$$$ walnut wood) on a .257 AI and that was the sexiest rifle and sexiest bullet combo I think I've ever seen.
FrankenMauser
New member
Hornady makes a .228" 70gr SP. (Though, strangely, Midway is listing it as .227" right now.RevGeo said:
)Just a reminder -
Clark blows guns up for a living. Take his "advice" with a substantial helping of salt. I have a lot of respect for the guy, but he really needs a disclaimer with many of his posts.