I have a Weaver K3 on my 35 Whelen. It has been on there for about 33 years. It has never fogged, or failed in any way. It has rusted a bit from time to time but the rust has not gone through yet. I have a K-4 on another rifle which has been in constant use since 1971. Still works fine. These scopes have seen conditions and abuse most never will. I think they are OK. GD
