Weavers are very relible as fixed power scopes. as variables I have had several failures.
I have had no failures with Denver Redfields or Burris FFII 2-7x35mm,
I have a Weaver 4.75x Grand Slam that is my "is it the scope?" test scope.
That said, my 2.5x FXII has held up fine on a few rifles, and sure doesn't seem to mind being on my 45/70