I have a lot of .22 rim fires that have not given a lick of trouble. out are made more than 35 years ago, some closer to a hundred years ago. My favorite just for casual plinking I would say are all my old WINCHESTERS. The ones I hunt with the most are clearly all my Marlin 39's. I don't know if any of this answers your questions or not?
+1 though I now only have 1 rimfire rifle- a Ruger 10/22 (which I bought new several decades ago. It has never given me any trouble, though I do keep it fairly clean. I remember working with someone years ago that had an old rusty (and I do mean rusty) Remington Nylon 66. This rifle was amazing in that it always seemed to function and hitting crows at around 50 yards or so was never a problem. With all this being said, the rimfire rifle I had many years ago but foolishly sold was a Winchester 9422. That rifle had the smoothest action of any rimfire I have ever held.
I don't know if any of the above rifles can be claimed as the "most bullet proof" but any of them will last for a long time (assuming reasonable care).
