HS-Armory Main Spring Shims

Main spring shims allow spacing of an AEG spring to increase FPS. These spacers are placed in the piston body and because of their construction are very light weight so will not effect piston weight very much. This kit contains 4 spacers in a geometric sequence that allow 11 different equally spaced adjustment levels. The small spacers are 1 adjustment level each, the medium spacer is 3 levels (equal to 3 small spacers in thickness) and the large is 6 adjustment levels. All stacked together is 11 levels. It should be noted that while a fair amount of spacing can be added without issue you should always check for the possibility of spring binding by measuring the springs fully compressed length (wire size times number of coils) and any spacing added by piston head or spring guide bearings. Approximate FPS increase based on spacer sizes is given below but of course this will vary based on other replica factors.

Specifications:
Small: ~1-4fps
Medium: ~8-12fps
Large: ~18-24fps
Total mass of all shims combined: ~1g