Spring 90 m/s FPS (FPS-90+)

The 90 m/s FPS spring has been calibrated on 363 mm barrels and gearbox with type D cylinder (for barrels from 301 to 400 mm).
Naturally, with shorter or longer rods the performance will decrease or increase, so you will switch to the harder or softer setting.
The thickness due to the spring guide and piston head bearings was not taken into consideration in the calibration process.
For this reason, given the same initial conditions, a performance increase of approximately 2.5 m/s for each bearing must be taken into account.
The FPS spring is 100% Made in Italy and was created in collaboration with leading companies in the sector.
The material used is burnished and pre-hardened carbon steel wire with the addition of silicon and chrome EN10270 / 2.
In the phase immediately following forming, the spring is stabilized in an oven at a temperature of 400 degrees centigrade for thirty minutes in order to optimize its durability over time.
The spring has variable pitch coils in the central area and in the area in contact with the spring guide and undergoes a grinding process at both ends which guarantees optimal performance during the compression phase.
The product dimensions are:
- length: 170 mm
- external diameter: 14.30 mm
It is recommended to use the spring in association with spring guides and bearing piston heads to ensure maximum performance and durability over time.