Home Forums Hunting & Shooting Hunting Rifles Rem 700 or Win 70

I never hunted dangerous game and I never had an extractor failure in any of my 700's. I like both Win 70 and Rem 700, but if I had fear of extractor failure in my 700 I would simply use one of my Win 70s. Or if I was using Rem 700 I'll have a good 44 mag revolver as a back up.
Question, what causes extractor failure, is it dirt or gummed up oils.