Someone posted the following comment on a product review site, and I'm interested in hearing what others think of what the author is saying about optical quality of scopes changing as we adjust the reticle towards the extremes. "A little info. When you sight in a rifle scope in, you have to adjust the windage and elevation knobs. The more you "turn and click" the scopes reticle from its factory set "centered" setting with these knobs, you less clear and accurate the scope becomes. Picture a cross hair reticle in your scope. And imagine at its factory original setting you can "turn and click" the elevation and/or windage knobs 100 clicks each direction. You do this to line up and sight in the cross hair with you bullseye target. But, each time you move your reticle cross hair up/down/left/right from its original factory setting, your are moving the reticle toward the "sides" of the scope, when its better and more clear to have the reticle in the center of the scope. Now, what these burris rings allow you to do is instead of "click and turning" your elevation and windage knobs to the extremes where they are near the "sides" of the scope walls, you can FIRST adjust the scope using these plastic inserts that go between the metal rings and the scope. So lets say you shoot your rifle at the target, and your a foot high and a foot to the left. Instead of turning your windage/elevation knobs a foot each way, you put the corresponding plastic inserts in the rings to adjust the scope from the OUTSIDE of the scope, rather than internally. After you do this a few times you will be within say 4 inches of the bullseye, and NOW you adjust the final few inches using your elevation/windage knobs. And because you did very little "turn and clicking" of your knobs, your internal reticle is near the center of the scope (rather than the outside edges), and because of this it is more clear and accurate. Ask any scope expert, they will tell you in perfect world the reticle is near the center like it is when it comes from the factory. This Burris rings and inserts allow you to do this. I also recommend using a one piece base, preferably all steel (could run you 100 bucks for the steel one piece base, but its more accurate and strong). I use these rings on my Winchester 70 .270 and Rem. 700 30.06"