Wildcat cartridges, sometimes referred to as simply “wildcats,” are custom-designed cartridges – meaning they are not mass produced, but instead made by individual shooters. The purpose of a wildcat is the cultivation of some attribute not sufficiently present in a commercially available round. Wildcats aren’t great for law enforcement or military purposes, but they are great for hardcore shooting aficionados, handloaders looking to take things to the next level, and gunsmiths who want to homebrew ammunition for their homebrew weapons.

The number of ways that a round can be wildcatted is theoretically endless, as there are thousands of wildcat cartridges created and available for gunsmiths and handloaders with a “can do” attitude. A wildcat round could be built from scratch from the ground up, but most are commercially modified. The equipment for reloaders and gunsmithing can frequently be found through the same distributors, which is another reason why shooters who are into one are frequently into the other. The wildcatting hobby is, unsurprisingly, concentrated in the United States.

A Brief History of Wildcat Cartridges

The term “wildcat” is derived from the same source as the other meaning of the term – a labor strike not authorized by the union brass. Wildcatting probably began after the American Civil War, when the .30-06 was considered by most shooters to be the only round that a hunter was going to need. American ingenuity and innovation, however, quickly decided that something more could be made out of the materials at hand.

In the late 1800s, Charles Newton was perhaps the first American to leave his profession (in his case, law) out of a desire to spend all of his time wildcatting. Along the way, he developed a number of rounds that became indispensable for shooters of his era. He tuned the .30-06 into the .25 Special and 7mm, which were the raw materials that crafted the 25-06 and .280 Remington. Newton wanted to build rifles more than anything, but circumstances beyond his control eventually shut down his business. In the end, he was the man who lit the fire of wildcatting in the United States – and many were more than willing to pick up where he left off.

Some of the first names to follow in his wake are legends among wildcatters in the know. These are names like Harvey Donaldson, J.E. Gebby, Grosvenor Wotkyns, John Sweaney and J.B. Smith. By the 1940s, Parker “P.O.” Ackley changed the wildcatting game by making small adjustments to rounds that greatly improved their overall performance. The most famous of this era, though, was Roy Weatherby, the son of Kansas sharecroppers.

Roy was earning $200 a week at the Automobile Club of Southern California in San Diego, which was a seriously solid wage back in those days. When the shop was closed, however, he used a lathe and a drill press purchased at Sears to make his own homebrew ammunition. Among these was the .220 Rocket, built off of a Swift parent cartridge.

Wildcatting developed as a way for the amateur shooter to tailor rounds for their individual purposes. This was commonly to comply with caliber or bullet weight permitting regulations for specific game, though performance also drove the rise of wildcatting. Metallic silhouette shooting is a popular field for wildcatters, as many competitors seek to adapt rifle rounds they can fire through their pistols. Autopistol hunters and competitors have also used wildcatting as a means to improve feeding.

Continue reading Wildcat Rounds: A Guide to Wildcatting and Customized Cartridges at Ammo.com.