American 180 is quite an unusual gun.
It was developed by Richard Casull in early 1970, as a continuation of Casull Model 290 rifle, which was developed ten years earlier. The rifle did not achieve much popularity, and only around 80 of them were manufactured overall.
Technically, American 180 is a submachine gun with simple blowback operation. It fires from the open bolt. Unusual is the high-capacity flat-pan magazine, and caliber - .22LR rounds.
Standard magazine for American 180 holds 177 cartridges in three layers, and is made from steel. Later models feature 3, 4 and 5-layered clear plastic magazines, with 165, 220 and 275 cartridges capacity respectively.
American 180 features high rate of fire - 1200 rpm. With magnum ammo - .22ILARCO, rate rises to even more formidable 1500 rpm.
This gun is often used by law enforcers - both in the field and in correctional facilities. Relative weakness of .22 ammo greatly diminishes risk of ricochet or overpenetration, thus making it preferable to more powerful ammunition for law enforcement.
Single .22 round is not capable of defeating flak jackets and other body armor, and therefore, American 180 was also considered to be relatively useless, if turned against police officers. However, practice shows, that with such high rate of fire, bullets literally eat through the armor and even concrete, though of course not instantly.
American 180 had a number of accessories and modifications - various barrel lengths, vertical front grip, optional laser aim and even mount for two/four American 180 linked together for stationary installations (primarily for prison posts).