Warren Center, working in his basement shop in the 1960s, developed a unique, break-action, single-shot pistol.

Although they cost more than some hunting revolvers, the flexibility of being able to shoot multiple calibers by simply changing the barrel and sights and its higher accuracy made it popular with handgun hunters.

[2] Originally the chamberings were on the low end of the recoil spectrum such as .22 LR, .22 WMR, .22 Hornet, .38 Special, and .22 Remington Jet, but as Magnum calibers took off in the 1970s, the Contender quickly became very popular with shooting enthusiasts.

Since the sights and extractor remain attached to the barrel in the Contender design, the frame itself contains no cartridge-specific features.

G2's with switchable firing pins (centerfire or rimfire) can be safely dry-fired with the hammer only in the safety (center) position.

[5] The earliest barrels, from early 1967 to late 1967, were all octagonal with a flat bottom lug, and were available in only 10 and 8+3⁄4 inches (250 and 220 mm) lengths.

[10] Pistol grips, butt stocks and fore-ends have been made available in stained walnut, or in recoil reducing composite materials.

The wood stocks and forend are made specifically for Thompson Center by a sawmill in Kansas.

[2] Calibers available for the Contender were initially limited, stopping just short of the .308 Winchester-class rifle cartridges.

Custom gunmakers have added to the selection, such as the J. D. Jones line of JDJ cartridges based on the .225 Winchester and .444 Marlin.

The degree of flexibility provided by the Contender design is unique for experimenting with new cartridges, handloads, barrel lengths, and shotshells.