I just sighted in my 25-06 with 100 grain barnes ttsx. Everything went well, the accuracy is 3/4moa from my sako 75 finnlight. But it was shooting in the dirt at first and I had to adjust 20 inches elevation. But thankfully I had enough adjustment to get a great 1-inch high zero at 135 yards. Do I really need to use a shim in this case? The erector tube is not close to being pressed against the outer wall. It is of course a little more to one side then the other. I believe the scope has 50 inches of adjustment if not more. We are talking about a Burris signature 3-12x50 made in 1994. It is an extremely accurate scope and it has helped me make some of the best shots in my life on prairie dogs. Is this asking too much of the springs or is it well within what it was made to do? Can I get some opinions here? I hate to take the scope out of the rings and shim it but if it is that important to have the erector tube centered then I am open to suggestions. Thanks in advance for anyone who helps out with my question. If it helps to know, this scope has two erector tube springs. When I look at the erector tube from the objective end, it doesn't even appear to be very far from the center. This scope may have more than 50 inches of adjustment. I just don't know for sure and I don't want to crank on it to find out because I love my zero right now.