Silverback SRS Variable Mass Piston

The Silverback SRS variable mass piston is an innovative product from Silverback that allows the user to finely tune the the FPS of the rifle by adding mass to the piston which through a travel force, forces air out behind the BB. By using different weights, the traveling force can be increased or decreased to allow the user to find a “sweet spot” where a desired FPS is achieved consistently.  The cap is also exceptionally soft and this translates into better air seal which adds to the consistency of each shot.