Ron Hoehn did one of the older Sightrons for me - not the newer Big Sky model. Ron stressed not to overtighten the nylon screws. If you want to change windage or elevation, loosen the screws, make the change, then gently retighten. This "fix" was in my budget.
I personally feel a frozen scope with Brackney or other external adjustable mounts might be a better way to go. I've also noticed some score shooters doing very well with Nightforce scopes
I realize many scopes are fine, but Mike Ratigan has a chapter titled, "Scopes: The Weakest Link." I'll take his word for it.
Tony Carpenter