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The 30-06 Ackley Imp in the New Centry

1393 Views 42 Replies 13 Participants Last post by  Darkker
The 30-06 Ackley Improved has been a controversial caliber since its introduction
in the late 40s-early 50s. PO Ackley felt it a good cartridge that tailgated the 300 H&H with slow powders
and heavy bullets. However, it depends on the individual rifle.
The early days of the 30-06 Improved had very few chronographs to confirm velocity with any bullet
weights. Hornady used their data to confirm that their test rifle used a small bit of extra powder to produce
very little change.

My Mauser 98 custom rifle increases velocity about 100 fps with 180- 225 gr Barnes originals
or 220 gr noslers. These are designed to get close to 318 Wesley-Richards velocities.I use H-870, H-4831,
and IMR-4350 powders. This rifle has early 1960-era B&L optics with provision for a Lyman 48 receiver sight.

Think long and hard about rechambering a 30-06 accurate rifle. With modern bullets like Swift, Nosler,
and Barnes offerings, the 30-06 & 06 IMP can be quite an excellent Alaskan or African rifle.
But it is not a 338-06 or 35 Whelen, or the improved chamberings of that rifle. The 30-06 Imp
chamber improved the life of brass and decreased neck trimming. Neck sizing and a seating die
can produce the right brass for the new chamber. Watch your chamber dimensions and OAL of cartridges
as compared to pressures and length of magazine. You might just get close to 300 H&H velocities
while keeping within safe pressures. Start 10% lower and work up.

Rocky Gibbs also had a famous 30-06 Gibbs Imp cartridge.
But making the brass was a real challenge.
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My Dad and Charlie O'Neill built one on an NRA surplus ($12 with shipping) 1917 Enfield in 1952. With a hatfull of H4350 (that's an actual reloading term) I can push a 180 grain Hornady Interlock to 2960 fps.

My oldest son's first elk in 2006



My first elk in 1964, I was 5. No, I didn't pull the trigger 馃槒



It used to have a K2.5 Weaver with a 6X Varmintmaster adapter in a King Pile detachable mount, but now it has a K6 steel tube Texas Weaver on it.

Technically it's a 30 OKH as Charlie built the reamer with more rounded edges on the shoulder and neck.



RJ
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The 30-06 Ackley Improved has been a controversial caliber since its introduction
in the late 40s-early 50s. PO Ackley felt it a good cartridge that tailgated the 300 H&H with slow powders
and heavy bullets. However, it depends on the individual rifle.
The early days of the 30-06 Improved had very few chronographs to confirm velocity with any bullet
weights. Hornady used their data to confirm that their test rifle used a small bit of extra powder to produce
very little change.

My Mauser 98 custom rifle increases velocity about 100 fps with 180- 225 gr Barnes originals
or 220 gr noslers. These are designed to get close to 318 Wesley-Richards velocities.I use H-870, H-4831,
and IMR-4350 powders. This rifle has early 1960-era B&L optics with provision for a Lyman 48 receiver sight.

Think long and hard about rechambering a 30-06 accurate rifle. With modern bullets like Swift, Nosler,
and Barnes offerings, the 30-06 & 06 IMP can be quite an excellent Alaskan or African rifle.
But it is not a 338-06 or 35 Whelen, or the improved chamberings of that rifle. The 30-06 Imp
chamber improved the life of brass and decreased neck trimming. Neck sizing and a seating die
can produce the right brass for the new chamber. Watch your chamber dimensions and OAL of cartridges
as compared to pressures and length of magazine. You might just get close to 300 H&H velocities
while keeping within safe pressures. Start 10% lower and work up.

Rocky Gibbs also had a famous 30-06 Gibbs Imp cartridge.
But making the brass was a real challenge.
In the Fifties and Sixties, the properly set back and re-chambered 30-06 ack. imp. was a hot ticket, as it held seventy grains of popular powders available then. The one I saw in my parents鈥 friend鈥檚 gun room even had a muzzle brake, looking like a Cutt鈥檚 Compensator. That was then, but Art bought a first Gen M 70, in the new 338 Win Mag, and used it on Canadian Moose hunts, up to the Seventies. Like a lot of post WWII ideas, they had their day when I was just a little kid.
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The HP White Labs testing in 1959 showed no real difference between the AI and standard 30-06. Hornady's relatively recently tested that to still hold true.
......except for your rifle, which has an extra 100fps; and also stays within "safe pressure limits".....

I'd dearly love to see your traces supporting this series of claims.
The workmanship on this stock and rifle is a compliment to the unknown riflesmith
who crafted it in Colorado. The chamber is tight while there is just a tad of freebore in the 24 in barrel.. Roy Weatherby did that on some of his rifles, and the early Weatherby's used a Mauser action.
One of my more effective rifles was a pre-64 Model 70 in 375 Weatherby which actually did
give improved ballistics with a Venturi shoulder. This rifle and slight waterproofing of the stock was done by Al Biesen
in the original rifle. It worked.
My proven best wildcat agreed with Ackley: The 348 Ackley Imp is close to perfect to use the improved 348 case.
The results on moose with a 250-270 gr Hawk, Woodleigh, or AL Bullet Works Kodiak bullets confirm chronograph increases of 150-200 FPS in all bullet weights. Popular in AK-Canada.

The 30-06 Ack Imp is an interesting cartridge, George Parker of Arizona Border Patrol fame used one, and I actually saw some of his older 50-yr old brass in a gunshop near Hereford, AZ in the 1980s-close to the border.

With the large steps made by bullet makers now like Swift and Barnes, there probably is no real reason to
step up the 30-06 case except to expand its neck, which I have done with success.

This rifles slight increase in velocity was confirmed by a sky-screen chronograph, but your results may differ.
Experienced shooters can also tell the difference in slight increases in range, penetration, or target elevation impact.
But the African hunters noticed more penetration with slightly reduced velocity, but this was before the days of Swift and Nosler. But they did use solids.

Both of my early Model 70 30-06s can tell, as one is a pre-war accurate rifle. They will get no chamber modification.
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Somewhere I saw some load data with pressure readings in CUP's which nowadays it a moot point.

I see Nosler is claiming 2985 fps with a 180 grain AB using Reloader 22 but they don't list pressures.

RJ
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My former business partner embraced the 30-06 AI with both arms and every ounce of his opinions. I built three for him and he loved them all, but there was nothing magic about it. Case capacity determines velocity (if all else the same), case shape determines how it feeds and the rim extracts. I'd rather have an H&H loafing along at moderate pressures than a higher-pressure straight case. That's where extraction problems show up. Its all a compromise between performance and reliability.
The 'improved' cartridges increase case capacity of the parent round and in rimmed cases moves the headspace dimension to the shoulder. That's all the 'magic' there is. The rest is perception and wishes.
If the purpose of a wildcat is to look different, the sky is the limit. Performance and reliability is set by dimensions and tolerances.
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The 338 AI is an excellent cartridge , as is the 338-06 with the 35 Whelen.
Both produce excellent results on larger game. I have one of each on two pre-64 Model 70s.
They are at the top of the heap for wildcats. The 338-06 is virtually the same as
the 333 OKH.

RL 22 is recommended for both the 30-06 and improved versions. If these velocities and pressures are safe in your individual rifle, then this means that re-chambering in 30-06 A Imp might be better served in investing in better powder and bullets.

But my Mauser custom M-98 came in 30-06 Imp and will remain this way. I am going to invest in some RL 22 because it works well, apparently/ This powder and Swift or Nosler 180 gr bullets might just be the right huckleberry for this Mauser.
Especially if accuracy remains a gilt-edged constant.
Case capacity determines velocity (if all else the same)..... The rest is perception and wishes.
That's correct, and it's why I asked for traces to corroborate the claims.
If someone isn't recording pressures, and specifically able to see the burning curve. Then they can't see whether or not the increased capacity is being actively taken advantage of, within the same pressure constraints. As you noted, not knowing this is the crux of the matter; whether or not all things are actually equal.

Knowing that volume shifts burning rates, simply adding more powder with the assumption that a powder is confined to the original burning rate; is a mistake without some justification for the proposition. In the actual testing of Ackley's AI rounds, the shift was enough to effectively negate the capacity advantage of the case; at least with the powders being used.
This is where most reloaders get lead astray, when they tell you that whatever case yields more velocity at the same pressure.
It certainly can do so, but it absolutely can also not do so.

Cheers
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.30-06 threads are pretty rare these days. So are .30-06 magazine articles and updates.

Really kind of amazing that something developed in 1906 or so, lasted so long, so well.
You are right.
But Phil Shoemaker, a guide in Alaska for decades, has made interesting comments on the 30-06, that
bears remembering. Those critical of it have probably never owned one-but are commenting on their own lack of experience and/or marksmanship. It is a cartridge now that is very effective with modern powders, like RL22 and
the new bullets now on the market.

I don't provide loading data or results specifically, as that should be up to the individual. There are also other forum
sites on the internet that are less critical and more informative as to technical details.
The 30-06 has accounted for much game over its lifetime, and has defended the US in many conflicts.
For hunting use, I find it superior to the .308 WCF-particularly with bullets heavier than 180 grains. The 30-06 AI
does have a place in the right rifle with modern powders.
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Not a thing wrong with the venerable '06 and in many camps it's still the "gold standard" as to which other cartridges have been compared. I now own at least 5 or 6 different rifles in '06, differing from each other from a Ruger #1A to a Sako 85, to a 45yr old 742.

If I want top tier performance out of a .30cal, these days I look to my various .300mags. Please note I worded that, "if I want" and not if I "need". If I want (or need) absolute top tier performance out of a .30 cal, I'll likely just choose one or another of my three .338mags.

It's likely true that many hunters might use "more gun" than necessary, but I find little fault with that IF you can shoot that gun well. It's nice to have choices and if someone feels that an '06 (imp or not) is the classic cartridge they feel fits the bill for them I'll clink my glass to yours while saying that I feel the same about my 45-70.
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In the Jan-Feb 1981 issue of HANDLOADER magazine, Earl Etter, Sr. reported on his
experience with a 30-06 Ackley Improved in a 22 in bbl Model 700 Remington.
My results mirror his with the exception that his rifle's throat is apparently longer than that
of my custom M-98 Mauser. My barrel is also 1.75 inch longer than Etters is. We both agree that RL-22 and other slow burners like H-205, H-4831 and 4350, along with the now rarer Norma MRP are best in this wildcat caliber.
His ballistic loading results are found on page 25, showing that some 30-06 Ackley rifles can do the business
with the right powders: H-205 and MRP. With Nosler 165 and 180 bullets, his rifle produced close to 300 H&H velocities of 3100 and 2990 FPS respectively-all within sane pressure limits, and safely used in both of our rifles. My Mauser 98 did have the advantage of a slightly longer barrel. My velocities were very similar with new fire- formed brass.
For those doubtful of the results-read the article-Handloader Magazine-Wolfe Publications online.

For the real doubting Thomas: build a custom 30-06 Ackley Improved 40-degree shoulder rifle, use MRP/ H-205/RL-22 extruded powders, and find out for yourself.
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1) his rifle produced close to 300 H&H velocities of 3100 and 2990 FPS respectively-all within sane pressure limits, and safely used in both of our rifles..

2) For the real doubting Thomas: build a custom 30-06 Ackley Improved 40-degree shoulder rifle, use MRP/ H-205/RL-22 extruded powders, and find out for yourself.
1) Did that article actually provide pressure measurements taken?

2) The "doubting Thomas" types have been listening, since such unfounded claims were first screeched by Ackley himself; and they sent it out for honest pressure testing. Which debunked Ackley's false and unsubstantiated claims of pressure, which he never honestly measured anyway.

Another major consideration every astute reloader has paired attention to, is the powders being referenced from 42 years ago. They have not been produced by those people, or with the same equipment and processes; nor with the same ingredients, for a significant amount of time.馃槈



Cheers
Etter substantiated his results with an Oehler Model 33 chronograph in 1981 within safe pressure guidelines.
HANDLOADER published the results. I duplicated them . If anyone cares to check the results,
build a 30-06 Ackley Imp rifle on a Weatherby or equally strong rifle-then check the results with the same recent powders for yourself.
NOT 1940s-or 1960s with those powders, but modern powders available now. Check the 1981 Handloader Magazine article and duplicate them with your results. Otherwise, HANDLOADER and Wolfe publications gets the credit
for a fine article with proven results. End of controversy.
The pressure thing is a bit much. Millions of reloads (probably hundreds of millions) have been fired with no idea what pressures were in the particular rifle. If the bolt opens, pockets are tight, case head hasn't expanded, etc. then pressures are safe. If that is 55K, 65K, 70k, no one will ever know, and everyone will be safe. 3.5 grains and an extra 5k pressure will increase velocity, if it is enough for someone to make one, then more power to them.
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For decades, with good reasons, reloaders have been warned to start 10% below a given
recommended loading. Here is why:
1. Rifles and chambers differ
2. Many factors may have an impact

Relative pressure factors: type and make of primer, make of brass and volume, strength of individual
brass case, powder make and lot, temperature- all may combine to spike pressures. Bob Hagel, a respected gun writer
with Wolfe Publications has for years shown maximum loads in his rifle tests with magnum, standard and wildcat cartridges including the 338-06 and 30-06. He always states the caveat of starting low and watching for pressure
signs. He backs his results with a chronograph. I also load for both a 338-06 and 35 Whelen in pre-64 Winchester Model 70 custom rifles.Today, more reloaders use chronographs or do not consider
handloads in rifles unless they have been reliably chronographed. Even then, it's best to start at least 10% below recommended loads and even older manual load recommendations.
That is all sound advise, and it supports my point that the actual pressure for the overwhelming majority of reloaders is irrelevant. If you are not exceeding maximum pressure in your rifle then you are operating in a safe manner. If my 338-06 can handle more of the same powder as yours, and produce higher muzzle velocities without mechanical issues then my loads are safe. If the loads in Ackley's book works in your gun without pressure signs then it is safe.

Of course, I have been known to run engines far beyond the parameters envisioned by the marketing geeks that held the reigns of the engineers that designed them, others have gone far beyond what I am willing to do sometimes with disastrous results. You do have to break a few eggs if you want to learn that particular lesson. Those who load until they have signs of high pressure and then decide where they want to stay have the highest performance. They burn through brass and beat up there firearms, but I don't get the mileage others get either.
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1) Etter substantiated his results with an Oehler Model 33 chronograph in 1981 within safe pressure guidelines.

2) build a 30-06 Ackley Imp rifle on a Weatherby or equally strong rifle-then check the results with the same recent powders for yourself.
NOT 1940s-or 1960s with those powders, but modern powders available now. Check the 1981 Handloader Magazine article and duplicate them with your results.

3) Otherwise, HANDLOADER and Wolfe publications gets the credit
for a fine article with proven results. End of controversy.
1) I didn't ask about a chronograph, I asked about pressure. Because you know that a chronograph doesn't record pressure...

2) This is the year 2023, and you're referring an article from 1981. 2023 - 1981 = 42 year old powder. The powders being referenced, are not the same; and in some instances have been changed multiple times already.

3) At no point did I claim it wasn't a wonderful article. What I challenged is badly out of date information about assuming pressures, and a false claim of knowledge.


. If the bolt opens, pockets are tight, case head hasn't expanded, etc. then pressures are safe. If that is 55K, 65K, 70k, no one will ever know, and everyone will be safe. 3.5 grains and an extra 5k pressure will increase velocity, if it is enough for someone to make one, then more power to them.
This is false, and dangerous information.
SAAMI sets the standards. When you exceed those standards, you have exceeded standard safe practices. SAAMI info is all freely available to read, as is the pressure sticky. Anyone interested in reloading should understand, the exponential decrease in lifespan when a pressure vessel is overloaded. Simply noticing that something didn't catastrophically fail, does not allow someone to proclaim "it's safe", or that everyone should do it regularly, or that they magically know something they aren't measuring.
Members since long before I began posting about pressure measurements, have been linking an extremely accurate and inexpensive measurement system. Moreover, as every twisting manual has started for an extremely long time: If you exceed book velocities, the presumption should be you exceed book pressures. If you want to actually confirm this, you buy the tools to measure it.

Bob Hagel, a respected gun writer
with Wolfe Publications... He always states the caveat of starting low and watching for pressure
signs. He backs his results with a chronograph. I.
A "respected" writer... One of those decided to join this forum, and begin bloviating about things he rather clearly didn't understand. He ignored almost a century of ballistic study, ignored some rather elementary facts about measurements, and ignored the wonderful pressure testing being shared here by those who came before me. His nonsense, is why I put my money where my mouth is, and actually began measuring pressure and his false claims; and sharing the results with the forum.


A chronograph measures velocity, not pressure.
When a chronograph informs you that there is excessive velocity, while it is a result of pressure; it doesn't actually tell you what the pressure is.
It certainly could be the case that the peak pressure is excessive. Or it could be that the area under the curve is greater, without an excessive pressure peak. Given the number of powders which are progressive in at least one application, the bumper sticker assumption people should default to; is that the peak pressure is excessive.


I've ridden several roller coasters in my life, and it felt like I was weightless at several points. That doesn't mean I actually was weightless, nor does it show me to tell people "I know" I was weightless. The only way I can say I know I was weightless, would be by measuring it. Telling a story about how quickly my ice cream cone melted that day, isn't measuring whether or not I was weightless. 馃槈

Cheers
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Most reloaders do not have direct access to pressure testing machines rigged to
test barrels. Powder and bullet manufacturers like Nosler, Hornady, Alliant and Swift do.
That is one reason modern reloading manuals and powder manufacturers have multiple
columns in their published data. As an example: IMR lists in their rifle data under the caliber:the powder,
bbl length, powder charge, velocity, and in the last column: chamber pressure.
They also publish the caveat on each page: " Velocity and pressure readings represent average values obtained under controlled conditions. We suggest that charge weights shown be reduced initially by 10% to compensate for possible
variations from the published the published data. The loads may then be increased as pressure indications permit."

Most powder/bullet manuf, manuals have similar statements or warnings as does the latest Nosler manual.
With all due respect, I tend to value the data in the latest powder manuals more than any actual loading data found on any forum or comparable site. That applies also to valuing the contents of Handloader Magazine above most forum contents.
There are exceptions but these are my own choices based on 50 years experience as a hunter in Alaska and
the inter-mountain West, in successful pursuit of elk, deer and moose and antelope using fair chase hunting principles.

My reloading standards also involve the value of my own firearms: an above average collection of Winchester pre-64 Model 70s, pre-war Model 71s, and smokeless-era 1886 rifles. Lever-action rifles require more attention to reloading details, as they have no sense of humor about chamber pressures in excess of their original design limits.

And then there is the value of my own hide. As a Vietnam combat veteran, I have personally seen the
damage that can occur to souls exposed to high concentrations of carelessness mixed with gun powder
and projectile velocity. Or being in the wrong place without protection...
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