I own 2 such scopes, one is a 3-9x40 Nikon that sits on top of my 243, it works just as good as the day I bought it, so no need to change it, also own a Leupold VX-2 which is also a 3-9x40, that sits on my 308, again it works great, so that won't be changed either. Both have seen use out to 300+...