A firearm barrel protective cover to prevent outside elements from entering a firearm barrel including a convex body partially surrounding the barrel end, the body having an outer wall, an opening disposed between first and second outer ends of the outer wall to accommodate a site member therethrough, and a channel disposed longitudinally within the wall. A disc-shaped flap is disposed abuttingly against a front end of the flap; and a continuous outside wall disposed between the forward end and the rearward end. An attachment member, including a hinge, pivotally attaches the flap to the body to allow gravity to swing and pivot the flap outwardly and downwardly away from the end of the barrel.