They can simply die without any particular warning. I love my 6x Leupolds but I have had to get repairs done.
I have a 243 that loves the 87 grain VMax. I had been using one of my 6x42 M8 scopes on it. Plinking at 300 yards on steel I could pour shot after shot into the same hit splash in the paint. Then one day I couldn't. Then it was all over the steel. Swapped on another scope and voila, all was well again.
