PGHaveFun

A coil drive style projectile designed to have spring-driven pop-out fins. It's mostly for the compact mechanism design. The primary mechanism is the torsion spring, which loads the fin-cam, which in turn actuates the fins. When they are in the aluminum (non-magnetic) casing, they stay closed, and then when the PG exits, the fins extend. *Note: The parts with number designations are from McMaster-Carr's website.