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.

6.5-284 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.