I have nearly 30 Leupolds at the moment. My kids and grandkids have another 12 or so I gave them or they bought themselves. A lot of my scopes that get a lot of use are 2-7 or 2.5-8 Leupolds. Maybe their light weight helps.
I have had one VXIIC (1989) windage failure. I sent it in, they fixed it and sent it back. It was on my pre-war Model 70 that was my main rifle until I got a SS M70 in the mid 90's. I also had a failure with a fixed 25x50 spotter - it came by it honestly..
Some point out that scopes don't fail because they don't get shot enough. They are certainly all on their way to breaking. That is certainly true of some of my rifles but others get shot a lot. My .338 went through two Bausch & Lombs before I put a 2.5-8x36 VXIII on it in 96. I was averaging about 50 rounds a week with it the first year I had it.
I have Leupold scopes on other rifles and in chamberings I might expect to have failures and so far so good. An 1885 .45-70, Talkeetna in .375 H&H, two Mini-14's, various slug shotguns, .300 mags, and a LW .35 Whelen among others.
I do have a lot of failures with some scopes. Tasco is ok if fixed power. Otherwise poor, Simmons is maybe the very worst. I have had poor performance from Bausch & Lomb-Bushnell but have two of their 4x Sportview scopes from the 70's.
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,
