MasterPiece Arms MPA5700SST 5.7x28

Like other MSA carbines, these have a left-side charging handle and a top rail for optics, and have standard-threaded barrels for universal silencers and muzzle devices. The ones in 5.7mm also have a pretty different grip style, and it isn't just to house the long small caliber cartridges. The MPA57SSTs are built with the Five-Seven in mind; they use standard FN magazines. Comes with an extended 30-rounder. The grip is also somewhat angled, not straight like it is on the other MAC-style MPA firearms.