"Modeled after the legendary HK53, the Century Arms AP53 Semi-Auto Pistol is a sub-gun platform chambered in the full-power 5.56x45mm NATO cartridge. If that sounds like a handful, it is. That's why the original HK53 earned the nickname ""The Beefy MP5."" It's loud, it's powerful, and it's a ton of fun to shoot. Like the original, the AP53 PDW utilizes the roller-delayed blowback action and features a stamped receiver and 8.3"" cold hammer-forged barrel. Other features include an ambidextrous safety selector, MP5-compatible wide handguard, and G3-pattern magazine. The AP53 PDW has been tested to NATO environmental standards for salt, fog, humidity, hot/cold, sand, and dust. Includes two 30-round magazines. Modeled after the legendary HK53 Chambered in the full-power 5.56x45mm NATO 8.3"" cold hammer-forged barrel with 4-prong flash hider Stamped receiver Fully adjustable rear sight/fixed front Ambidextrous safety selector switch MP5-compatible wide handguard Includes 2 HK33-pattern 30-round magazines"