The AR15 is called a modern sporting rifle and not an assault rifle. A semi-automatic or self-loading firearm is a gun that after being fired ejects the empty cartridge that has been fired, then loads a new cartridge, and re-cocks itself and is ready to fired again. Rifles within the AR15 platform are among the most popular rifles and carbines being sold today for small game hunting as well as target shooting. AR15 rifles and carbines look like the M16 and M4 carbine used today by the U.S. Military. The M16 and M4 are classified as fully automatic firearms. Fully automatic firearms ownership is regulated by the federal government, states and local city and county laws. Many states do not allow ownership of machine guns, but many states do allow private ownership of machine guns. The AR15 holds different capacities of magazines to include 5,10,20 and 30 round box magazines. The AR15 is also available in a variety of calibers. The standard caliber for the AR15 is .223 Rem/5.56mm NATO. AR15′s and magazines for the AR15 are made by such manufacturers as Bushmaster, Colt and Magpul just to name a few. The AR15 in .223/5.56mm can also be converted to 22lr by using a 22 conversion kit made by CMMG. To find out more about AR rifles checkout AR15.com