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Top Cats

Top Cats

Six of today's most popular wildcat cartridges.

Quick, name the six most popular wildcats in the country! Most popular? Based on what? And these days, what is a wildcat cartridge anyway? Good questions, all of them, with the last being the thorniest and most difficult to answer.

In the older, simpler days, a wildcat was a cartridge designed by a private citizen and chambered in a custom rifle. Ammunition was available only by necking down, blowing out, trimming, fire-forming and, ultimately, handloading.

The accepted definition of a wildcat was a cartridge for which no commercial rifles, ammunition or brass was available.

That was an easy definition in the days when we had a few big rifle and ammunition companies. Today, with a small rifle shop around every corner, finished brass being produced in various garages across the country, and even small ammunition makers flourishing in specialized markets, it is not so easy to call even the most obscure cartridge a genuine wildcat.

As for determining which of these feral felines is the most popular, who can really say? Talk to a rifle maker who specializes in benchrest rifles and he'll tell you one thing; a maker of hunting rifles will tell you something else, and guys who make varmint rifles have yet a third view.

Wildcat cartridges have one common denominator, however, and that is loading dies. Every wildcat owner loads his own (otherwise, why get one?), and to do this they need dies. So our first two stops were Redding and RCBS, the dominant makers of custom loading dies.


"Probably the top of our list is the 6.5-284 (a .284 Winchester necked down to 6.5mm)," said Kurt Nelson of Redding, and that view was backed up by Chris Murray, retail sales manager at E.R. Shaw, the maker of custom barrels. Shaw will barrel a customer's action to any cartridge, so they know exactly what those barrels are becoming. As well, Rob Behr, technical services manager at Cooper Arms of Montana, says the 6.5-284 is "a huge seller for us."

No. 1: 6.5-284
The 6.5-284 is the current darling of long-range benchrest shooters. Although it has been around for a long time, its current popularity is partly due to the rise in recent years of the unbelted "short magnums," a group that the .284 resembles, and pre-dates, by many, many years.


Bullet diameter: .264 in.
Max case length: 2.170 in.
Max overall length: 2.800 in.
Case capacity: 65 grains water
Typical max-load velocities
100 grain - 3,400 fps
120 grain - 3,000 fps
130 grain - 3,000 fps
140 grain - 2,800 fps


The .284 Winchester was introduced in 1963, chambered in Winchester's short-action Model 88 lever rifle and Model 100 semiauto. The .284 is .308 length, but its fat body gives it powder capacity and performance similar to a .30-06 case, and its rebated rim adapts easily to .30-06-size bolt faces. The cartridge is a natural for wildcatting, and over the years it has been necked up and down to virtually every caliber.

For years, long-range shooters have admired the 6.5mm (.264) bore diameter, and the wonderful ballistic performance of heavy (140 grains and up) bullets in this caliber. The 6.5-284 marries the advantages of a short case and compact powder column with the ballistic prowess of heavy 6.5mm bullets.

An excellent target cartridge, it is also a first-rate hunting round if one wanted to go to the trouble. Since most hunters do not, this accounts for the No. 2 cartridge on our list.

No. 2: 6.5-06
This is Chris Murray's nominee for No. 2, although it figures farther down on Redding's list of die sales and does not appear on the RCBS list at all, except in an "improved" form (more about this later).


Bullet diameter: .264 in.
Max case length: 2.494 in.
Max overall length: 3.340
Case capacity: 65 grains water
Typical max-load velocities
100 grain - 3,400 fps
120 grain - 3,100 fps
130 grain - 3,000 fps
140 grain - 2,800 fps


The 6.5-06 may or may not qualify as a wildcat, and it certainly boasts the strangest ancestry of any cartridge on this list. The 6.5-06 really began life in 1913 as the .256 Newton. The Newton cartridge was actually a .264 but followed the old European practice of naming the cartridge after bore diameter rather than bullet or groove diameter.

Charles Newton was an eccentric cartridge- and rifle-designing genius from Buffalo, New York. He also designed the .22 Savage Hi-Power and .250-3000. His rifle company lasted but a short while, but his cartridge designs live on — although usually under other names.

So the 6.5-06 has been a popular wildcat based on the .30-06 case for almost a century now, and everything said about the 6.5-284 applies equally, since the two are ballistically identical. Really, the only difference is the longer, thinner case of the 6.5-06 and the ready availability of brass and ease of case-forming.

Several small ammunition companies have attempted to standardize the 6.5-06 without success, and there has been much hand-wringing among writers who tout its virtues and despair at its lack of acceptance. Ah, wel

l, a wildcat's life is not a happy one. Wonderful cartridge, though. Thank you, Charles Newton.

Nos. 3 & 4: A Pair of Ackleys
Parker O. Ackley was a rifle maker and wildcatter and author of a handbook on reloading. He is most famous today for a clutch of Ackley Improved cartridges. Ackley would grab any existing cartridge, steepen the shoulder, blow out the case to near-parallel walls and tack "Ackley Improved" onto the name.

.257 Ackley Improved

Bullet diameter: .257 in.
Max case length: 2.230 in.
Max overall length: 3.065 in.
Case capacity: 60 grains water
Typical max-load velocities
75 grain 3,600 fps
87 grain 3,300 fps
100 grain 3,100 fps
115 grain 2,900 fps
120 grain 2,800 fps


In some cases, any improvement in performance existed only in Ackley's imagination. But in others there was a genuine boost in powder capacity and velocities, and these are the cartridges that are still popular.

The two that are currently favored are the .280 Remington Ackley Improved and the .257 Roberts AI. The .280 is second on the Redding list and third in the estimation of Chris Murray at E.R. Shaw. The .257 is Chris's fourth choice and also appears on the list provided by Rob Behr at Cooper Arms.

"We get more requests for the .280 AI than any of the other Ackley cartridges," said Murray, "And it really is a fantastic cartridge. You can load it to almost equal the factory ballistics of the 7mm Remington Magnum."

The old .257 Roberts is the basis for the .257 AI. It is originally a wildcat cartridge itself, which writer Ned Roberts created by necking down the 7x57 Mauser case. Because the original case has quite a bit of taper, and because Roberts kept a very gradual shoulder, there was substantial scope for Ackley to "improve" it by blowing it out and steepening the shoulder.

.280 Ackley Improved

Bullet diameter: .284 in.
Max case length: 2.525 in.
Max overall length: 3.330 in.
Case capacity: 70 grains water
Typical max-load velocities
120 grain - 3,300 fps
140 grain - 3,200 fps
150 grain - 3,000 fps
160 grain - 3,000 fps


"The .257 AI is one of our best sellers, and deservedly so," said Rob Behr. "It is one of the best of Ackley's designs and gives the most improvement in performance."

No. 5: .20 VarTarg
Rob Behr at Cooper Arms puts the .20 VarTarg at the top of his list by a wide margin.

.20 VarTarg

Bullet diameter: .204 in.
Max case length: 1.400 in.
Max overall length: N/A
Case capacity: 23 grains water
Typical max load velocities
32 grain 3,700 fps
36 grain 3,600 fps


"It is by far our most-produced wildcat cartridge in our rifles," he says. "It is a good 250-yard varmint cartridge, with a relatively quiet report. And it has a very small appetite for powder."

The .20 VarTarg is the creation of Todd Kindler, editor of Small Caliber News. It is the old .221 Remington Fireball case necked down to .204. As well as making little noise and eating tiny amounts of powder, the .20 VarTarg is also remarkably easy on barrels.

"We sell a lot of them to woodchuck hunters in the East who hunt in built-up areas and don't want to make a lot of noise," Behr said.

Second on Behr's list, and for similar reasons, is the even more miserly .17 Ackley Hornet -- the .22 Hornet case blown out and necked down.

No. 6: .224 TTH
E.R. Shaw's Murray lists the .224 TTH on his top six list. "TTH" stands for Texas Trophy Hunter, and it is used primarily by whitetail hunters, in Texas and similar areas, where steady shots are made from stands.

.224 TTH

Bullet diameter: .224 in.
Max case length: 2.233 in.
Max overall length: N/A
Case capacity: 55 grains water
Typical max-load velocities
55 grain 3,800 fps
60 grain 3,800 fps
79 grain 3,500 fps
75 grain 3,800 fps


The cartridge was created by writer Ralph Lermayer in 1998. It is the 6mm Remington necked down to .224. The rifles have fast-twist (1:8 or 1:9) barrels and use bullets that are heavy for caliber. Velocities can exceed 3,500 fps, and the choice of bullets becomes critical. T

he advent of good hunting bullets created specifically for this type of application, such as Nosler's .224-caliber 60-grain Partition, make this a good deer cartridge in areas where it is legal.

The foregoing list is subjective, to say the least. No national polling mechanism exists to determine which wildcat cartridges are the most popular at any given moment. But, looking at the cartridges listed, and also those who were also-rans, occurring further down everyone's lists, it is possible to draw a few conclusions.

First, as a group, Ackley's "improved" cartridges probably lead the pack; if you include slight variations on that theme, which are really AI cartridges under another name, then there is no question that that is where most of the interest lies among those who are buying rifles for hunting.

Many cartridges now have "40" tacked onto the name, meaning the cartridge has a 40-degree shoulder -- steeper than the original and usually coupled with a blown-out case for maximum powder capacity. These cartridges really are little different than the Ackley designs. These "40" cartridges dominate the RCBS list of loading dies in most demand.

Two classes of cartridge are conspicuous by their absence from our list: the rimless short magnums of recent years and belted cases. For many years, it seemed the majority of wildcat cartridges were based on the .375 H&H belted case; today, in terms of popularity, they are nowhere to be found.

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