Got a Nikon scope on my t/c encore and it won't hold zero. Tried many times to get it sighted properly but just doesn't hold zero Its a 3x9x50 mm pro staff . Has any body used there no fault warranty ? I was reading the repair instructions and it's got to be original owner and you need proof of purchase . I don't keep up on paper work like that and bought it mounted to my gun . The set up is a few yrs old