Barrel Cots Gun Barrel Protectors from Birchwood Casey is an easy way to keep debris, rain, snow, mud, bugs and more out of the barrel of your firearm. Simply roll the Barrel Cot onto the barrel of your firearm, when you're ready to shoot, go right ahead. The Barrel Cot does not have to be removed and does not reduce your accuracy whatsoever. It protects the muzzle of your gun without sacrificing any performance! One size fits all barrels, whether it is a pistol, rifle, shotgun or muzzleloader. 20 Cots per bag.