M150 main
spring

The main spring is designed to be
used in tune ups of the electric replicas (AEGs), the spring is uneven, what
significantly extends the lifespan of the system  by minimizing the
spring”s clumping effect, of course under the condition that the spring is
mounted in a proper manner. It is made by the well known G&G company.

In a typical system, the spring
allows to fire the BB pellet with the muzzle velocity of about ~500 FPS. Yet it
is important to remember that the final muzzle velocity gained by the mount of
the spring depends on the sealness of the system, the type of the used
cylinder, the length of the barrel and its diameter. The ends of the spring
were grinded what results in its better operation.