Gun scope and action cover comprises a water-proof, breathable / air-permeable, reversible, light-weight, highly-flexible fabric pouch formed by an enclosed, cinchable elastic cord that fits over the optical scope of a rifle or hand gun, and that is universal in size, quiet in use, easy to put on and take off, and easy to store. The pouch area, formed by cinching and locking the cord, is bounded with an extended skirt that drapes down over the mechanical action of the gun. 2-ply waterproof / breathable fabric is preferred. Additional features include a securing cord for adding camouflaging ghillie strips, hook and loop fastener silencer(s) that prevent accidental adhesion to clothing, the release of which causes game-spooking sound, and a pocket for a warmer unit. The cover employs a variety of camouflage patterns on one or both sides, or one side may be a dark, a light, or a safety color, such as neon orange.