(17)
(A) The term “ammunition” means ammunition or cartridge cases, primers, bullets, or propellent powder designed for use in any firearm.
(B) The term “armor piercing ammunition” means—
(i) a projectile or projectile core which may be used in a handgun and which is constructed entirely (excluding the presence of traces of other substances) from one or a combination of tungsten alloys, steel, iron, brass, bronze, beryllium copper, or depleted uranium; or
(ii) a full jacketed projectile larger than .22 caliber designed and intended for use in a handgun and whose jacket has a weight of more than 25 percent of the total weight of the projectile.
(C) The term “armor piercing ammunition” does not include shotgun shot required by Federal or State environmental or game regulations for hunting purposes, a frangible projectile designed for target shooting, a projectile which the Attorney General finds is primarily intended to be used for sporting purposes, or any other projectile or projectile core which the Attorney General finds is intended to be used for industrial purposes, including a charge used in an oil and gas well perforating device.
Is someone making a handgun that uses this ammunition?
Lots of people: .223 handgun
There are AR-15/AK-47 type handguns and single shots like the TC Contender can be chambered for almost any cartridge.