I recently took a scope off of one rifle and transferred it to another rifle. Upon attempting to sight in the new scope/rifle combo, I have encountered a problem with achieveing any sort of a zero. After boresighting the rifle and firing the first round, I made the neccesary adjustments to get a good "ballpark" beginning. After several more shots and adjustments failed to bring me anywhere close to my zero I became frustrated and decided to turn to people who know a little bit more about these kinds of problems. I have made sure that all my rings and mounts are tight. The scope worked perfectly on my old rifle as well. The new rifle that it has been mounted on is a Ruger MkII chambered in .308 Win. Any suggestions would be helpful. Thanks in advance for any advice.