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The .280 Ackley

The .280 Ackley

Mild-mannered but wicked, the .280 Ackley Improved is a virtuoso of a cartridge.


I'll stick my neck out and say it: I think the .280 Ackley Improved cartridge is the finest of the flock and gives shooters more for their effort than any other wildcat.

(Some may argue that it's no longer a wildcat, what with Nosler currently providing its custom ammo. However, the .280 AI's heritage is so decidedly feline that I'll take the liberty of referring to it as such.)

P.O. Ackley (1903 - 1989), who designed the round, was a master of "improving" standard factory cartridges. By the simple device of opening up a typical SAAMI-spec chamber to have less body taper and a (much) steeper shoulder, he created a larger, more efficient propellant chamber, yet he did so in such a manner that the standard parent cartridge would still function and safely fire in the improved chamber. The key element enabling this was that Ackley's chamber maintained the original dimension from the head of the cartridge to the juncture of the neck and shoulder, allowing both his improved version and the factory parent version to headspace properly.

When chambered in a fine rifle like this Nesika Hunter Model V, the .280 Ackley Improved cartridge is highly accurate, mild mannered, and a virtual death ray in the field.

Cases obtained by firing--and thus fireforming--standard cartridges through Ackley's improved chamber could be handloaded to give improved performance. Accomplished handloaders coaxed performance rivaling that of magnums out of their rifles. Cases also stretched less, allowing longer case life and necessitating less frequent trimming. And in a pinch, owners of Ackley-chambered rifles could pick up standard ammo at the local hardware store and usually get at least hunting-grade accuracy, so these wildcats didn't suffer from any "can't get ammo" stigma.

Though Ackley tried at one point or another an improved version of almost every cartridge available in his day, only a few gave performance worth performing surgery on your favorite rifle for. Of those by far the most enduring is the .280 Ackley Improved (AI), and for good reason: It performs more like a 7mm Remington Magnum than a standard .280 Remington.

Why, you may ask, not just get a 7mm Remington Magnum? Because the .280 AI has less muzzle blast, less recoil, and more rounds snugged into that box magazine, for starters. And panache? The .280 Ackley has panache to spare.


It is popular enough that Nosler both chambers its fine rifles in .280 AI and produces .280 AI in its custom line of ammunition, as well as providing component brass for handloaders that would rather not take the time to fireform cases. Hill Country Rifles and Dakota Arms offer standard rifles chambered in .280 AI, as do most custom riflemakers worth their salt. Also, almost any existing .280 Rem. rifle can easily be re-chambered to the Ackley version. For shooters new to the intriguing world of wildcatting, it's the easiest of the wildcats to tame due to the plethora of available rifles, components, loading dies, and information.

I'm not a veteran of the .280 Ackley, though I've carried a secret crush on the cartridge for years. My personal experience with it began last fall with a fine custom rifle built by Dakota Arms that utilizes a Nesika Mark V action.

The Nesika Action

Read it by clicking HERE


Mentored through late summer and early fall by friend, writer, and .280 AI aficionado Chub Eastman (who has, last I heard, 18 one-shot kills to the credit of his .280 AI), I developed a fantastic handload for the Nesika. The 150-grain Barnes TTSX bullet loaded over 59 grains of Alliant Reloder 19 exits the muzzle at 3,061 fps. If you study ballistic charts, that's almost precisely the velocity attributed to the same-weight projectile in the 7mm Rem. Mag. Best of all, the load is accurate. The most recent group I shot at 200 meters--yes, 200--measured 0.8 inch.

Both Hornady and RCBS make .280 AI dies. The cutaway case shows the increased internal capacity offered by the blown-out cartridge walls and steeper shoulder angle. Also shown are some of the author's favorite projectiles for the .280 AI. Bottom Left to top Right: Barnes 150-Gr. TTSX, Hornady 139-Gr. GMX, Nosler 160-Gr. AccuBond, Swift 150-Gr. Scirocco II, Sierra 160-Gr. GameKing, Remington 140-Gr. AccuTip, Remington 160-Gr. CLUB

Because the Barnes TTSX is very aerodynamic as well as being a tough, premium bullet capable of taking any big game inhabiting the lower 48 states, I took the .280 AI on back-to-back Wyoming pronghorn and Colorado elk hunts.

Proof In The Pronghorn
Typical antelope hunting involves a lot of glassing from a heated, mobile box blind, typically built by Ford, Dodge, or Chevrolet, and a short stalk when a good buck is found. Not this time. A torrential rainstorm had just passed through northeastern Wyoming. Great for the crops, but with the local variety of Bentonite clay, anything but blacktop and well-graveled roads were impassible. Hunting partner Chris Ellis and I earned our pronghorn the old-fashioned way. We didn't mind; it turned what is usually rather a mellow affair into

a real hunt.

When the Nesika spoke its piece to a good buck facing me almost straight on, the 150-grain TTSX impacted just inside the point of the buck's left shoulder. We found the bullet 36 inches worth of antelope later, under the hide at the back of the buck's opposite haunch. Needless to say, the buck dropped on the spot. The bullet had expanded perfectly and retained 99.5 percent of its original weight.

Elk Country
Several days later found me in the Colorado snow, hiking up a very steep canyonside with my friend Justin Ludwig. When we found a good bull, he was in a tiny pocket across a deep, wide canyon, and there was no way to get closer. We studied on it for at least half an hour. Finally we decided that I must take the shot or lose the opportunity.

This Colorado bull was shot across a wide, gnarly canyon where the advantages of the .280 AI in a highly accurate rifle really came into play. Justin Ludwig Photo.

I won't even admit how far it was, but I was very confident in the rifle/cartridge combination and its ability to place the bullet precisely where it needed to go. And I had the time to run some mental calculations to confirm that the 150-grain TTSX bullet would still be traveling at or above 1,900 fps upon impact, giving it the needed velocity to expand properly for a clean kill. And finally, I was using a Zeiss 4-16X 50mm Victory Diavari FL scope with the company's Rapid-Z reticle--superb for those times when you really need to push the distance envelope.

Powders legendary in the .280 Ackley Improved are Reloder 22 and H4831. They performed well in the author's Nesika rifle, but Reloder 19 gave spectacular results with the 150-grain Barnes TTSX.

I worked my way into a good rest involving a small scrub oak, an Under Armor glove, and a lot of snow. When the bull turned broadside, I squeezed off the .280 AI. "You hit 'im," Justin grunted, and as I worked the bolt the solid "thump" of a well-placed hit floated across the canyon. The bull was into the scrub oak before I could shoot again.

Forty-five minutes and one small canyon-bottom river-crossing later, we approached the mountainside pocket with care, ready for the bull to explode from the brush like a small locomotive. It was unnecessary; he lay quiet in the bloody snow, shielded by a canopy of tiny oaks. The bullet had taken the arteries off the top of his heart and passed through both lungs, putting him down in just a few seconds. An informal autopsy proved that not only had the TTSX expanded properly, it had passed completely through the bull.

I'm a standard-cartridge fan. I love the .30-06 Gov't. and .270 Win. I like the slick way they feed, I like having five rounds on tap, and I prefer the slender actions that house them.

.280 Ackley Chambers Improved

Read it by clicking HERE


I use and appreciate magnums, but I don't love them. The .280 Ackley Improved provides honest magnum performance with every advantage of a standard cartridge.

Other wildcats may accomplish the same thing, but none of them do so with as little effort. Long live P.O. Ackley's greatest creation!

NOTES: Velocity is the average of five rounds measured 12 feet from the gun's muzzle with a Shooting Chrony chronograph. Reduce loads a full 10 percent and work up carefully to avoid dangerously high pressures in your personal rifle's chamber.

WARNING: The loads shown here are safe only in the guns for which they were developed. Neither the author nor InterMedia Outdoors, Inc. assumes any liability for accidents or injury resulting from the use or misuse of this data.

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