3It's important to clean rifles and pistols to preserve accuracy, and for shotguns, particularly semi-automatics, to prevent them from jamming or misfiring. When a center fire rifle is fired, powder leaves a residue as it burns, called powder fouling, and the copper jacket on the bullet leaves a residue as it travels down the barrel called copper fouling. These residues build up after every shot, particularly the copper fouling. This buildup of residues will be greatest at the part of the barrel in front of the chamber where the rifling starts, called the throat. Once this buildup gets large enough, say after about 20 shots, it sizes each bullet as it passes it. Since the sized bullet no longer exactly fits the bore, an amount of accuracy is lost. Even if this build up is only .002 to .003 inch in thickness, it will reduce accuracy. Properly cleaning the bore is the only way to prevent this buildup of residues and resulting loss of accuracy. If the barrel of a center fire rifle is not cleaned after firing 20 shots or more, the powder and copper residue will chemically bond and be ironed into a compound harder than the steel it adheres to. Once this happens, it can't be removed without damaging the barrel and accuracy is forever lost. This includes the .17 HMR, .17 Mach 2, and .22 Magnum rim fire rifles, which also have copper jacket bullets and travel at high velocities. While properly cleaning the bores of pistols and standard .22 caliber rifles is also important to prevent the loss of accuracy, since these bullets travel at much lower velocities, these guns only need cleaning after about every 100 shots. And, periodic cleaning of shotguns is the only way to insure their reliable functioning. According to gunsmiths, improper cleaning techniques have ruined the accuracy of as many rifles and pistols as not cleaning them at all. This booklet takes you step-by-step through the correct process of cleaning center fire rifles, rim fire rifles, shotguns, pistols and black powder rifles - bolt actions, lever actions, over/under, semi-automatics, assault rifles and revolvers.