I need some knowledge laid on me from the optics experts. I know three ways of "centering" a scope (which is something you want to do if you are using a mounting system that has some adjustment in it.)

"Counting Clicks" - This is the method that seems most recommended, I suppose because it is easy enough and requires no special equipment. If you have a windage adjustable mount, it seems this would be the best way to insure that you were left with the most elevation adjustment.

"Mirror Method" - With some scopes, you can stand it up vertically, objective end down, on a mirror, look into it, and see two images of the reticle. You can then adjust things to make the images coincide. It seems to me this method most centers the optics "relative to themselves" regardless of any manufacturing variations in the placement of optics in the tube or optics in relation to the windage and elevation adjustments.

"Spin the Tube" - Some place the scope in "V" blocks, sight on a distant point or pattern, and then adjust so that the reticle stays centered (crosshair intersection does not move in a circle) as you spin the scope. Obviously, this centers the reticle relative to the tube (assuming the tube is straight, and it may not be perfectly straight.)

Now, in a perfect world, I believe all three methods would coincide. But, the world is far from perfect.

Do I have a good understanding of what each of these methods achieves? What is the most recommended method, or does it depend on the situation?

Thanks so much,
Gun Doc

I use the counting clicks or KISS method.

I use the mirror method because it's fastest and I can't lose count.

MichiganScott,

I like that method too. However, it doesn't seem to work with my new SWFA 10x42. I cannot seem to find two images of the reticle. It may have to do with which "plane" the reticle is in.

I've used all three methods, but to be honest I usually mount the scope and go shoot.

What Gundoc said about the mirror method centering the scope "relative to itself" makes an awful lot of sense. I've done the click and count method very carefully before, then checked it with the mirror and it would be 5-6 clicks off from actual center. If the obj. is firmly squared with the mirror I don't think you can go wrong.
John

Me too if I don't have an adjustable mount. But if you do have such a mount, then it is a good idea to start out with a centered scope.

John,

I have had the same experience, and I don't know why. For all I know, it may have to do with the quality and flatness of the mirror as well as any "unsquareness" in the scope. As long as it is not too far off, I don't worry about it. If it was way off, I suppose I would be calling the manufacturer, often Leupold in my case.

Gun Doc