Info needed on the Bushmaster .223 - yes I researched & no this is not pro or anti

[1-Old-Man]

13. .223 is, in the generic sense, "22 caliber"

Bullets are defined by their diameter, if you round .223 down you get .22, or twenty-two-caliber. The Bushmaster is a model of rifle, it is probably produced in several calipers, just as any one of a couple of different engines or transmissions might be put in your car without changing its model name. The AR-15 is produced in .223 caliber (which when converted to metric measurement equals 5.56MM) a caliber that was adopted by the US during the war against Viet Nam when they started issuing M-16 rifles. It is a much smaller round than its predecessor (M-14 with .308 caliber).

The standard .22 that you are probably thinking of is a bullet with a very small case, so it holds little gun powder and in the end the power of a bullet is very much a function of the size of the case that holds the powder. The .223 case holds many times the amount of powder that a .22 in any of its several versions (.22 short, .22 long, and even a thing called a .22 magnum).