Sometimes when you mount a scope – something just aint right and you can’t get the scope aligned properly to get it bore-sighted. Slight errors in the making of the base or rings or something… Many reasons… but the result is that to get the scope bore-sighted right, you have to shim the scope. Don’t panic. And don’t go off and order some expensive Shim Kit. And don’t use Paper shim. They compress and get thinner over time. You don’t need to spend any money… well, maybe 75 Cents at most. You can make your own Shims. It’s easy to do, and I do it all the time. I am a professional, and I’m telling you – you can do this at home. It’s Ballistic Science, but it’s not Rocket Science. All you have to do is to make some Beer Can Shims.