AR57 12" Complete ULT M-LOK Upper Receiver 5.7x28 Caliber With BCG, Muzzle Brake, M-LOK Rails and 1-50 Round Mag, Drop In Ready

Convert your AR-15 type pistol to shoot the same 5.7x28 ammo as the legendary FN P-90 PDW!

This AR57 Upper is constructed with a steel barrel, muzzle brake, bolt carrier group, buffer, and screws, all built into an alloy monobloc receiver. In other words, it is ready to drop in and push pin.  It is also built as solid as a tank. A single block of Aircraft Grade 7075 T6 aluminum, referred to as Kryptonite Monobloc and rated at 83000 PSI strength, is used for the receiver and its component rails. Precision milled to within .002 tolerance, this upper is chambered in 5.7 x 28 mm.