FPS 100 m/s spring (FPS100+)
BRAND FPSUPGRADE +.100 m/s FPS spring has been calibrated on 363 mm inner barreland gearbox with type D cylinder (for barrels from 301 to 400 mm).Of course with shorter or longer barrel the performance willdecrease or increase, therefore the calibration will be harder or softer.In the calibration process has not...