The .357 SMG by Zen Armaments is a submachine-gun/pistol cartridge created for the company's .357 Submachine Gun.
The .357 SMG was first used in its namesake, the .357 Submachine Gun. It soon after was adopted for use in the Zen Arms .357 Pistol. It is designed to be a high-velocity, deep-penetration caliber with satisfactory body armor penetration.
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