Which Ackley Improved Improves the Most??

[Minnesota1]

I haven't been able to locate a reasonably priced P.O. Ackley book(s). I know some of the Impoved cartridges don't give much extra bang for the buck. Would you rate the best Improved cartridges that give the best improvement over their standard counterpart? Are the best the 22-250, 30-30, 257 roberts, 223? If you can rank them accordingly, as many as you want to, I would appreciate it or if you have a comment or commentary on the cartridges or their effectiveness, etc. I would like that as well.

Thanks,

Bob

[Graybeard]

I'm not sure there is a definitive answer to the question. The .30-30 surely is one of the top but I seem to recall the .250 Savage is generally rated as most improved. The .22 Hornet also can gain much but generally the K-Hornet not the AI is the way to go with it.

To my mind tho the most desireable to me are the .257 Roberts AI and the .280 Remington AI with the .30-30 AI trailing them for use in a TC Contender if made as a new barrel not a rechamber.

[yooper77]

Any of my Ackley Improved cartridges, I benefit from less cases stretching than from more speed also my 7mm Mauser Ackley Improved and 30-06 Springfield Ackley Improved cartridges burn slow burning powder more efficiently that standard cases.

Reduced case stretching is tops in my book, I don't care about more speed, just accuracy.

yooper77

[Lone Star]

P.O. stated of the .250/3000 Improved that "it is one of the best of the so called Improved cartridges.  It shows a greater percentage of increase in velocity than almost any other."



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[Catfish]

If your asking which case has the largest increase in velocity it would be the one the with the largest increase in volume. The increase in velocity is 1/2 of the % increase in case volume, or so the rule goes.

[Doesniper]

The 30-40 Krag AI also has a very nice improvement over the standard round.

[iiranger]

Mr. Ackley was a trained engineer. Syracuse Univ???  Read his books and he makes the point that he "improved" cartridges to reduce the back thrust on the action and to keep the burning powder in the case extending barrel life and sharpened the shoulder to slow case lengthening. The extra velocity was "gravey on the taters."

He writes of firing a 94 Winchester, .30/30 Improved, without the bolt locking lug in the gun. [NOT from the shoulder!] The improved case gripped the chamber sufficiently that the bolt stayed in the gun.

Obviously taking a funnel shaped case like the .22/250 and straightening out the sides to reduce back thrust also greatly increases powder capacity. More powder, more velocity and more cost. More funnel eliminated, more performance. He wrote the .30/40 Krag Imp, NOT IN Krag rifles (one locking lug and OLD) would equal the .300 H&H factory ammo. (.300 H&H was not loaded hot for use in places that are hot, Africa, India, etc.) .38/55? Nothing to improve.

So if you hunt a couple times a year for meat in the Rockies. Get up close. 50 yards or less. Shoot the young and dumb good eating, tender animals... factory .30/30 is o.k. As the distance gets greater, improving the same gun to .30/30 Imp and reaching the performance of approx. the .300 Savage makes the work a bit easier. At the same time you need custom dies... you burn more powder... Will you use the gun enough to make it a good investment or is this a toy without regard to costs?

When I was young and dumb, I asked by letter about improving the .308. Most graciously he pointed out to me that there wasn't much to gain. Body was almost straight already. Compare the .308 to the .300 Savage improved and what do you see. Longer neck on the .308.

.257 Improved treads on the heals of the .25/'06 with lighter bullets. Heavy bullets and more powder helps. Of course, the Bob (.257) was standardized at 45K CUP, thus the later +P loads.

So what do you want/need? You want top velocity (the .300 Ackley Magnum was out long before Mr. Weatherby began his "marketing" work) You want longest case life? Or will any factory gun get the job done once a year when you go out with the boys? (and girls???) [Or are you the one who stays behind with the girls...]  The books are a treasure. Keep looking. eabco.com lists them. Third volume reportedly in the works but that has been forever. ?? Great foundation for anyone with this kind of interests. Mike Bellm, bellmtcs.com bought out Mr. Ackely. No idea if he has any books around. You could ask. Luck with your learning.

[Freezer]

   OK that was interesting!  Is there any advantage to 6.5 Swede AI to the 6.5 Swede?  I have an Arg. Mauser I've been working on and it's time for a barrel.

[Lone Star]

Mr. Ackley was a trained engineer. Syracuse Univ???  Read his books and he makes the point that he "improved" cartridges to reduce the back thrust on the action and to keep the burning powder in the case extending barrel life and sharpened the shoulder to slow case lengthening.

Actually, P.O. sold us all a bill of goods with all his claims of 'reduced back thrust' - his mechanical engineering degree suggests he knew the truth .  The thinking man already knows this too.   Back thrust is controlled by the strength of the brass, not the case shape.  Remember the incipient head separations so common on some magnum brass and the likes of the .35 Remington?  That happens because the front portion of the case expands to grip the chamber walls, while the un-expanded thicker part of the case is slammed back against the breech, stretching the case if there is room or just transferring thrust if there is not.  Most cartridges already do what Ackley claimed only his did.  The .30-30 trick described in the above post has no science behind it and it is easy to demonstrate that it does not show more than slight-of-hand.

Note that I respected Parker a lot while he was alive, he built several rifles for me in the 1970s and we corresponded some.  But he was in business to make a living and this 'back thrust' thing was just marketing.  To me the real benefit of his 'so-called improved cartridges' (his term) was the increase in case capacity and thus the increased velocity.  He still stands as one of the all-time leaders in firearms technology and design.

A fine explanation of Ackley's Mistake  along with tests debunking his claims can be found in the November 2004 issue of Precision Shooting magazine.



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[roper]

Here is a good article from PS on the Ackley
http://shootersforum.com/showthread.htm?t=5813

[Boxhead]

I'd guess the 348 Win.

[nomosendero]

Ackley Chart:     http://www.4-dproducts.com/ackleychart.php

[41 magnum]

The Sierra manual says the .257 AI is the MOST improved, followed by the 250 Savage AI.
I know the 257 will do whatever the 25-06 will do, with 3/4 the powder.
Shootingly,
41mag

[Lone Star]

The .257AI is a wonderful cartridge (I sold mine in a fit of idiocy years ago) but it is not  the equivalent of the .25-06.   I believe this is important for new reloaders to realize - there is no magic in cartridge design, and the cartridge with the greater powder capacity will give higher velocities at the same pressures.   It will also use more powder, but that difference is certainly not linear, as the pressure-tested data below shows.  Anyone can overload a .257AI cartridge to increase its performance, but then the same can be done to the .25-06...

Using the Sierra Manual referenced above:
.257AI - 100@3200 fps - 44 gr
.25-06 - 100@3400 fps - 53 gr....6% faster with 20% more powder

.257AI - 117@2900 fps - 44gr
.25-06 - 117@3100 fps - 49 gr...7% faster with 11% more powder

Using the Nosler #5 Manual:
.257AI - 100@3222 fps - 44 gr
.25-06 - 100@3345 fps - 57 gr....4% faster with 30% more powder

.257AI - 120@2974 fps - 51 gr
.25-06 - 120@3090 fps - 52 gr...4% faster with 2% more powder

It is interesting to note that their own data puts the lie to what is written in the text for their .257AI data.  Sierra states:
"In fact, this version is far more efficient than the .25-06, producing essentially the same performance while using substantially less powder"
Most shooters would not consider a shortfall of 200 fps to be "essentially the same performance".  That would mean there is no difference between the .257 and the AI versions.   And is 11% "substantially less powder"?  Too often, what is written in the text of loading manuals bears little resemblance to what the loading data shows.

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[nomosendero]

Yes, it goes back to what we should already know. Pick the performance level with ALL the factors considered, in other words velocity, barrel life, trajectory, wind drift, etc. What overall performance do WE want? Efficiency has relevance, to some more than others & to me it has relevance, but it falls well behind the other factors previously stated. It is a fact that the 25-35 or 250 Sav.
is alot more efficient than the 25-06 or 25-06AI, but it is not relevant to me, as the performance does not match my personal goals.
So we strike a balance of what we want & that is what matters, none of us should give a rip about what others think of our choices.
Sometimes the AI rounds give me something I want & I use them, sometimes they don't & I use something else, just the way it is. If we draw false conclusions about the performance of a given round, then did not research the round logically. And some folks will do that well after this thread goes away.   

[Tom W.]

I rechmbered my rifle to 30-06 A.I. because I wanted to, not necessarily for increased performance.

[onesonek]

I haven't been able to locate a reasonably priced P.O. Ackley book(s). I know some of the Impoved cartridges don't give much extra bang for the buck. Would you rate the best Improved cartridges that give the best improvement over their standard counterpart? Are the best the 22-250, 30-30, 257 roberts, 223? If you can rank them accordingly, as many as you want to, I would appreciate it or if you have a comment or commentary on the cartridges or their effectiveness, etc. I would like that as well.

Thanks,

Bob

A few have already been mentioned like the 30-30, 30-40, AND .250 Sav.. Rounds such as these and rounds in general, that first in the commercial state are relatively low or modest pressure rounds. That and those like these with a fair bit of taper in which to increase capacity. Those are cases AI'd will give the most return. Then it's pretty much up to the particular firearm likes and dislikes, as to what actual gain in performance may be achieved.
The .22-250 has lots of taper, but is a fair high intensity round since it was stanardized.  You will see capacity increase, but on the lower end of velocity gain when you look at AI comparisions. The others as in like .257Rob. and those based on the 57mm case, in general were loaded to modest pressures and have modest gains in capacity, but still warrent AI'ing in my mind.

Dave

[jelsr]

I have both of the Ackley books and it seemed to me he was favoring the 3 57mm AI's, the 257, 270, and 7mm. I have a 257 and a 7mm myself and both are very good. As far as the 257 vs the 25/06, the 257 is more effecient with lighter bullets and as the bullet weight goes up the 25/06 gets better. My 257 is 1 in 12 so I can only shoot up to 87 gr before the accuracy starts going away. Just built the 7mm and still trying to find out what it prefers. 52 gr 4350, 139 spbt gets just shy of 3050 and 2" groups.


Jim

[wmurrell]

As far as pure improvement, I believe it is a tie between the 25-35 AI and the 300 H&H AI as far as increase in capacity.

[Arizona Jake]

Even better than the .257 Ackley Improved and the 25-06 is the .25-06 Ackley Improved, also known as "The Poor Man's .257 Weatherby". Yes, it's a barrel-burner, but for hunting big game at extended ranges where a FLAT trajectory is important, only the Weatherby beats it.

[Lone Star]

"This is one of the best of the so-called Improved cartridges.  It shows a greater percentage of increase in velocity than almost any other.  In spite of its superlative characteristics it is the least heard of cartridge in the entire series....it is very efficient and flexible and deserving of much greater popularity than it has heretofore enjoyed."

The quote is from Parker Ackley, speaking about his .250/3000 Improved.


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[bcp]

Ackley Chart:     http://www.4-dproducts.com/ackleychart.php

The problem with that chart is that it bases the percentage improvement not on case capacity, but on velocity.  This does not account for possible differences in loading pressure between the standard and the improved cartridge.

For example, compare the 25-35 and the 219 Zipper.  The cases are so similar in their tapered shape they should have about the same improvement in capacity.  But the chart shows the 25-35 gaining about 25% while the 219 Zipper gains about 6%.

Anyone have a chart that shows capacity increase for AI cartridges?

Bruce

[mauser98us]

I will admit I built my 35 whelen AI out of an emotional need. It just looks so cool!

[DonH]

I recently spent some time poring over Ackley's reloading book. Comparing his data for his cartridges with other more recent pressure-tested data confirmed in my mind what I had long suspected: Mr. Ackley achieved his gains as much by "tipping the can" as by "improving" the cases.  "Tipping the can" is a term for a practice used by old Top Fuel and Funny car racers when they needed to go just a bit faster: they would just "tip" the nitro can, adding a greater percentage of nitro to their fuel mix. Yeah, they went faster but often got violent booms also. They are now limited to a certain percentage of nitro in the mix; so also should reloaders adhere to sane pressure levels.
Wildcat cartridge loading data developed before ready availability of chronographs was mostly done just about this way. When all the hype is cut through, often the real gains from "improaving" a cartridge is the extra work involved and some really neat-looking cases. It really does improve some rounds though...

[nomosendero]

Ackley Chart:     http://www.4-dproducts.com/ackleychart.php

The problem with that chart is that it bases the percentage improvement not on case capacity, but on velocity.  This does not account for possible differences in loading pressure between the standard and the improved cartridge.

For example, compare the 25-35 and the 219 Zipper.  The cases are so similar in their tapered shape they should have about the same improvement in capacity.  But the chart shows the 25-35 gaining about 25% while the 219 Zipper gains about 6%.

Anyone have a chart that shows capacity increase for AI cartridges?

Bruce

Vel. is the performance improvement percentage I am interested in & it is the same for most people.

If the cap. increase is your interest then I would pick the cartridge you are interested in and then research the data,if cap. increase is your interest, you wouldn't need it for all the cartridges anyway.

[skb2706]

From a 'case life', elimination of trimming and shear volume of potential rounds.....22-250 AI hands down. Not huge gains in speed but does wonders to case life and I don't trim anymore. I load 20 times more rounds in varmint calibers than big game calibers.