Now that I have thoroughly lamented, the Peacekeeper V-32 is a high-power, anti-armor SMG using the now less proprietary 5.7x28mm SS190 ammo, which was known to penetrate body and ceramic armor of light thickness. The armor-piercing properties of that cartridge was put into a reliable, assault carbine package, combining excellent stopping power with ease of handling.
However, it received a bad reputation among BO2 players, as its extreme stopping power from short to medium range can down a player with 2 to 3 shots, otherwise known as "over-powered".
(P.S. Just wait until StraightUpKnives uses this...)