A&K MK43 (M60E3) completely modified -Polarstar Jack -Bullgear HopUp -Prometheus Purple Bucking -Madbull 6.03 Barrel Gun runs fine on 35rps. Any more and the box mag cannot keep up. It has been tuned to run about two box mags (5500 bbs) on a 47ci 3000psi tank at 80psi (1.5j). Comes with regulator and coil remote line. Throw a tank and battery on and go rain BBs. 500 plus shipping G&S firm.