My 2 redfields failed. 1 new one crosshair wire broke on my first shot at a deer with it. One fogged up after using 25 years. Had both repaired. The 3 Leupolds I have on CF rifles have all at some point started shifting around and not reliable enough for ethical hunting. and one shifted way left and wouldn't adjust to the.right. 2 were repaired. One is 3 years old and I am sending it back soon. I don't drop or bang my rifles around. I have never had a rifle fail.
I have had a Browning A-5 Shotgun firing pin break on a hunt away from home and foolishly hadn't brought a backup gun. I had used it 35 years though.