GMT M100 Spring

This is a M100 spring made by GMT. It should do about 360 fps but this could be way off depending on your gun. This is a dual stage spring, which means the coils get farther and close together in different parts of the spring. This is the way all aftermarket springs are while stock springs are constant rate. It changes how much force the spring applies at different points in the stroke. The medium velocity of this spring makes it best for higher rate of fire setups operating in the woods or open areas.

Features:
- About 360 FPS
- .054" (1.38mm) wire diameter
- Best for high speed medium range setups

UASR rating: 2.94DR
Spring rate (6kg test): 583N/m
Spring length: 174mm
More information on UASR ratings here and here.