Gun barrel caps

A barrel cap comprising:

• a body having a generally cylindrical wall which extends from a first side of a generally planar end wall, and an opening defined by the generally cylindrical wall opposite the generally planar end wall, the opening configured to receive a muzzle of a gun barrel within the generally cylindrical wall;
• a first set of ridges extending from an interior side of the generally cylindrical wall and axially aligned with the generally cylindrical wall, each of the ridges of the first set of ridges having an apex configured for contact with an exterior surface of a gun barrel proximate to a muzzle end of the gun barrel;
• a second set of ridges extending from an exterior side of the generally cylindrical wall and axially aligned with the generally cylindrical wall, and
• the end wall extending radially beyond the second set of ridges.