Covers for key lock mounting systems on small arms such as the AR or M4 family of rifles and carbines can provide protection for the firearm and comfort for the operator. The cover has keyhole grips that are pressed into the key lock mounting points in mounting system. The cover is held seated against the surface of the mounting system by the shape and resilience of keyhole grips. V-notch keyhole grips can attach to keyhole shaped mounting points and slot shaped mounting points.