Working on mounting a Nitrex TR-1 on my new .223 & am running into problems. I am using Weaver 46M, P/N 48502 base mounts & Weaver 49046 1" Medium Quad Lock rings. The problem is the rings are too far apart to allow proper clamping to the tube. What part did I buy wrong? A newbie at bolt action rifles so please be patient. Want to get it set up so I can start shooting it in. Thanks in advance, Andy.