I had an H&R pocket revolver possibly 50 to 100 years old that had some bad springs, which broke while cleaning them, a Star 9mm where the firing pin broke which is a common thing I have read, a Byrco 9mm where firing pin had broke on it, a safety that would slide back to the safe position while firing it on a Norinco Tokarev, and one time while trying out a 1911 that I had assembled with parts I traded for at a gunshow, I tried out some handloaded ammo that my buddy gave me, thats when I learned, never never, ever shoot ammo that someone else has reloaded, unless you know them. The stuff was very hot and it destroyed all the parts that I had just put on it. The barrel busted in four places where the cracks ran full length of barrel, the slide split in 2 places from the barrel bushing back to the ejection port, the barrel bushing busted sending my guide rod spring and retainer flying off, and my frame had a couple of places up front that were flaired out. I was very suprised that I had not been hurt or killed, all that from someone elses reloads, not sure what the exact cause was but that it was result of the ammo. It could have even been an obstructed barrel from a bad round. I think that proper cleaning or routine cleaning will help a person to see the condition of their firearm, and familiarize them with it better, as well as the obvious results of helping it run more effectively, efficiently, and safely. But from my humble experience, most problems happen with the age and usage, I respect firearms enough that I do not abuse.