Victorcharlie, I have used the 2" Ultra Varmint 15x for 44 yrs now and I have never had any trouble with it at all. I really like them. When you shoot the gun the scope moves forward and back again. That is what the spring is for. It has external adjustments. The glass is real good in them. I don't know about the new ones but some of the people that work there bought the factory and make them like John Unertl did. Carl L.