Prometheus MS120 Non-Linear Spring

Excellently manufactured spring in the usual outstanding Prometheus quality with a non-linear design for optimal performance and durability. The nominal value of the spring strength indicates the expected value in m/s (meters per second) with 0.20g ammunition and can be multiplied by a factor of 3.28 to achieve the value in fps. The stated nominal value is only a guideline; the effective firing power depends on the tuner's skills and the system's sealing. With correct installation, the effective value typically deviates less than 10% from the nominal value. Experience shows that the effective value is usually higher than the nominal value, so in case of doubt, always opt for the next weaker spring. To achieve the desired muzzle velocity as optimally as possible, various components and combinations (springs, piston head, cylinder head etc.) often need to be tried out. For systems with particularly good sealing (e.g., KWA G2X), significantly lower nominal values must be chosen.