"Cleaning a barrel will shorten its life." That's the "factormyth" scenario a viewer submitted to our Smyth Busters, Brownells Gun Techs™ Caleb and Steve. Is it true? The barrels of .22 rimfire guns are made of softer steel, and careless cleaning with a screwtogether, sectioned steel rod without a bore guide CAN lead to permanent damage to the rifling. Ammoniabased solvent, commonly used to remove copper fouling, can pit the bore if it is not thoroughly flushed from the barrel. Copper fouling on .22s isn't difficult to remove with regular bore solvent, so there's usually no need for an aggressive ammoniabased solvent. Longrange precision rifle shooters clean their barrels a LOT, and their barrels do tend to wear out because of the high number of rounds fired, not due to the cleaning. Cleaning a barrel regularly with a good polymercoated cleaning rod will in no way shorten its life, especially if it's a chromelined or Nitrided barrel. So the myth that cleaning wears out a barrel is BUSTED as long as you're not a heavyhanded cleaner. Fouling degrades accuracy and reduces bore life, so go ahead and clean your barrel AS NEEDED.