Very seldom would I have an optic fail until I bought a 475 linebaugh. 1 ultra dot,a fixed 2x swift ( toughest scope ever) and a cheap variable. I quit running 420's at 1400 and my issues ceased. I haven't tried Leupold as I'm not a huge fan of them. I just reduced the load and ran it. Not happy about it, but is what it is.