Description 140 m/s FPS spring has been calibrated on the original sniper rifle. Of course with shorter or longer barrels the performance will decrease or increase, therefore the calibration will be harder or softer. In the calibration process, the bearings of the spring guide. So, starting with equal initial conditions, you have to take into account a performance increase of about 2.5 m/s for each bearing. The FPS spring is 100% Made in Italy and it is produced in collaboration with leading companies in the sector. The material used is steel wire burnished and pre-hardened carbon steel with the addition of silicon and chromium EN10270 / 2. In the phase immediately subsequent to forming the spring is stabilized in the oven at a temperature of 400 degrees Celsius for thirty minutes in order to improve its durability. The spring has coils with a variable pitch in the central area that is in contact with the spring guide and undergoes a process of grinding the two ends which guarantees optimal performance in the compression phase.
