Precision parts 4S M4 hop-up chamber Precision parts ZERO 6.02 mm inner barrel – 229 mm Precision parts ZERO 6.02 mm inner barrel – 300 mm Precision parts ZERO 6.02 mm inner barrel – 340 mm Precision parts ZERO 6.02 mm inner barrel – 363 mm Precision parts ZERO 6.02 mm inner barrel – 380 mm Precision parts ZERO 6.02 mm inner barrel – 430 mm Precision parts ZERO 6.02 mm inner barrel – 450 mm Precision parts ZERO 6.02 mm inner barrel – 455 mm Precision parts ZERO 6.02 mm inner barrel – 509 mm Precision parts ZERO 6.02 mm inner barrel – 550 mm
