” MasterPiece Arms (MPA) is now producing a FN 5.7x28mm short-barreled rifle with a folding wire stock. This gun expands on their line of Defenders chambered in 5.7x28mm, which offer shooters some options that are markedly different than FN’s Five-seveN and PS90. Called the MPA57SST-SBR, this follows their carbines and pistol also chambered for the exotic cartridge. 

 

 

 

The MPA Defenders are based on the Military Armament Corporation’s M-10, aka the MAC-10. They have been updated with a side charging handle, a top rail for optics and have a quad-railed forearm for accessories. The MPA57SST-SBR comes with a Cobra grip by Strike Industries, a angled foregrip with a hand stop that also acts as a standoff device for shooting from cover. 

Like the other Defenders chambered in 5.7x28mm, the pistol grip has been modified to accept standard Five-seveN magazines, which are available in 10-, 20- and 30-round capacities, and comes with one 20-rounder from the factory.”