Slugthrower Personal Defense Weapon

A personal defense weapon (PDW) is a compact select-fire firearm similar in most respects to a submachine gun. Most PDWs fire a small caliber, high velocity bottleneck cartridge, resembling a small or short rifle round. This gives the PDW better range, accuracy and armor-penetrating capability than submachine guns, which fire pistol-caliber cartridges. The class of weapon as it exists today evolved as a hybrid between a submachine gun and a carbine, retaining the compact size and ammunition capacity of the former while adding the power, accuracy and penetration of the latter.

Applications
The PDW concept has not been widely successful, partly because PDWs are not significantly cheaper to manufacture than full size assault rifles. PDWs use a proprietary cartridge which was originally compatible with any existing pistols or rifles. A different take on the PDW concept is a special high-pressure armor-piercing version to give it similar capabilities as other PDWs.

Though personal defense weapons have not been very popular for their intended application, they have been acquired by many special forces and law enforcement groups as direct replacements for submachine guns.