The .243 Winchester is a popular sporting rifle

Rifle

A rifle is a firearm designed to be fired from the shoulder, with a barrel that has a helical groove or pattern of grooves cut into the barrel walls. The raised areas of the rifling are called "lands," which make contact with the projectile , imparting spin around an axis corresponding to the...

 cartridge. Initially designed as a varmint round, it is now more frequently used on medium to large game such as whitetail deer, mule deer

Mule Deer

The mule deer is a deer indigenous to western North America. The Mule Deer gets its name from its large mule-like ears. There are believed to be several subspecies, including the black-tailed deer...

, pronghorn

Pronghorn

The pronghorn is a species of artiodactyl mammal endemic to interior western and central North America. Though not an antelope, it is often known colloquially in North America as the prong buck, pronghorn antelope, or simply antelope, as it closely resembles the true antelopes of the Old World and...

, wild hogs, and even black bear

American black bear

The American black bear is a medium-sized bear native to North America. It is the continent's smallest and most common bear species. Black bears are omnivores, with their diets varying greatly depending on season and location. They typically live in largely forested areas, but do leave forests in...

 and caribou. However, due to the smaller caliber bullet used, its suitability for large animals is dependent on skill level and the hunter's ability to make a clean and accurate shot. The .243 is based on a necked down .308 cartridge case and is known widely for its accuracy, flat trajectory, and relatively mild recoil.
This cartridge was first introduced in 1955 for Winchester

Winchester Repeating Arms Company

The Winchester Repeating Arms Company was a prominent American maker of repeating firearms, located in New Haven, Connecticut. The Winchester brand is today used under license by two subsidiaries of the Herstal Group, Fabrique Nationale of Belgium and the Browning Arms Company of Morgan, Utah.-...

's Model 70 bolt-action and Model 88 lever-action sporting rifles and quickly gained popularity among sportsmen worldwide.