The 223 Remington was introduced to the public as a commercial cartridge by Remington in January 1964 chambered in their Remington model 700 bolt action rifle, most ar15's are chambered for this cartridge as well. One month later in February 1964 this same cartridge was officially standardized by the U.S. military as the 5.56mm ball cartridge M193 and is used in m16's and m4 autoloading rifles, several years later this cartridge was accepted by NATO as the 5.56x45 NATO cartridge. Many years of testing and development were required to produce this cartridge, the actual name .223 Remington was given to this cartridge in 1959, prior to 1959 this cartridge was, aka; .222 Special.
The one point I would like to stress here, is, the fact military 5.56x45mm NATO cartridge ball ammo is loaded to different pressure levels to work in military rifles with different chamber and throat dimensions than the commercial .223 Remington versions. Military Ball Ammo can cause higher pressures in 223 Remington commercial sporting rifles with shorter free bore area inside the barrel. Military chamber specification rifles will fire either cartridge with no problems.
The 223 Remington is one of the top varmint and predator rounds in the United States. With so many variations of rifle action types, surplus ammo, range brass, bulk bullets, the .223 Remington will remain at the top of the sales charts for a very long time. With so many states allowing .22 center-fire rifles for big game hunting, Winchester ammunition now produces 223 Remington Deer and Hog loadings with 64 grain bullets in their Power Core, Power Max, Power Point and Razorback loads and they seem to work more than adequately for thin skinned game animals when broad-side shots are taken. The .223 Remington has adequate broad-side shot penetration for deer out to 100 yards with specialized ammunition. Hard angled raking shots should be avoided.
The 223 Remington is a light recoiling cartridge, easy to reload and fun to shoot, just remember to use only commercial 223 Remington ammunition not 5.56 ball ammo, if using ball ammo make sure your firearm has been altered to military chamber specifications.