I have a Glock 17 that is well over the 100K mark. At some point, a rear slide rail broke but the gun was still functioning. Glock replaced the frame and rebuilt the pistol free. I also wore out the mag release on that pistol and replaced it myself. I have a Rock River AR I bought about 20 years ago that I have completely burned out 3 barrels with- first the original Rock River, followed by 2 GI barrels. The last time a barrel gave up, I replaced the entire upper with a mid length complete upper PSA had on sale for less than $300. It is my instructor/training gun. I have also broken hammer and trigger pins, dropped a hammer J-pin, broke a cam pin, sheared a bolt lug, broken the ejector spring into about 6 pieces, replaced the gas rings many times, broken the front pivot pin, wore a perfect impression of the bolt lugs into the bolt stop, and wore large grooves into 2 buffers on that gun. I decided to nickname it "clunky". About the only original part still remaining on it is the lower. It is a true "frankenstein" gun, since it has been brought back from the dead so many times with whatever was available. If I were to consider using it for anything other than a range toy, I would scrap everything except the lower and start fresh. Couldn't even begin to guess the round count on that thing. It was my instructor gun during a period when ammo was very plentiful and totally free.