I have a wee Winchester lever action in .22 that has had an uncountable number of rounds through it. It is still unbelievably accurate. It will be near 30 years old now.
I was given it by a mate who had 2 of them as he was shooting so many rabbits at one point. If I were to guess it must be well over 50,000 rounds (probably a gross under estimate to be honest)??? Only thing that has ever needed done to it is the screw that holds the stock onto the action once needed tightened. The friend who gave it to me has always said if he had to keep just on gun in the cabinet to survive with, it would be the .22rf...
My kids love it and refer to it as the 'cowboy gun'.