Action Army VSR-10 M170 Spring

The Action Army VSR-10 M170 Spring is an upgrade spring for all VSR-10 models from various brands that own the VSR-10 line.

We regularly get the question which spring gives which fps / joule, which is very difficult to estimate because it depends not only on the spring what this value will be after placing the spring. The air seal of the cylinder, piston and piston head also have a large share in this.