I stopped in at Sportsman's Warehouse in Portland today while I was up there on business.

Was checking out some potential scopes for the rebarreled 22/250. One of the guys behind the counter did not really know about resetable zeros on some of the scopes that have them. So I was showing him how to do so.

Guess he felt " unknowlegable" so he had to save face. He showed me one of the coolest yet simplest things I have seen in a long time. Indicated that the guys over at Leupold across town had shown him this.

Just before you mount a scope, and YOU want to see if your windage and verticle knobs are in synch with the cross hairs?

Take a small mirror and set the scope down on the mirror, with the objective down on the mirror standing straight up.
You can see the cross hairs reflection on the mirror and see where the ones in your scope are, in ratio to the where the windage adjustments currently have them.

Turn the windage adjustments and you will actually see the cross hairs line up with the one's reflected in the mirror.!!!

I thought this was so cool!!! I asked where he got that from and that is when he told me he was shown it by one of the people from the repair dept at Leupold.

Then when the scope is mounted on the rifle, it does not take much to bore site it at all at that point.

Now I just have to appropriate one of my wife's mirrors from out of her bathroom.......

Cheers and good shooting
seafire

This is pretty cool. If I'm not mistaken, when they line up it shows that the scope is optically centered.

What it does not show is if optically centered corresponds with mechanically centered, nor does it show if your mounts are lined up. That last bit is important if you expect an easy sight-in.

But still, pretty cool.

So is it better to start with the scope optically centered or mechanically centered?

Good question, and I don't know the answer but alittle experimenting will quickly answer it.

What I was shown, is that the scope was off the rifle and was mechanically centered. This should make sure that your scope is set up centered when mounted on the rifle.

Next, once it is one the rifle, put a mirror on the edge of a table and you can rest the scope against the mirror and check to make sure it is still mechanically centered once mounted on the rifle. That will tell you that your scope mounts are centered.

I gather Leupold does this test right off when a scope comes in for repair with complaints of accuracy. If It fails that test, they know what dept or section to send it to immediately.

Plan to play with this a little more this afternoon when I am done visiting clients ( working, ugh) and get to understand the prinicipal a little more clearer, and its application. Escpecially since the rain is stopping me from finishing putting a new emergency brake cable in my 4 Runner.

Cheers and Good shooting.
seafire

Seafire/B17G: Thanks for the neat tip! I did not know that! I always "mechanically" center the adjustments on used scopes that I am remounting. Then I "bore sight the scope to the rings/mounts" before lapping the bottom of the rings and tightening the top rings down.
So next time I am re-mounting a scope I will do both centering tests of the scope. Your method with the mirror and the old method of counting adjustment turns and then dividing by two and centering the adjustments mechanically. It will be interesting to compare the results of the Leupold mirror method and the mechanical centering!
Thanks again!
Hold into the wind
VarmintGuy

I have always centred the scope optically -- and I've never yet run out of scope adjustments unless I'm trying to zero beyond 500 metres.

I set the scope in V-blocks (you can even cut two V notches in a cardboard box). Rotate the scope as you look through it and adjust the click adjustments until the crosshairs don't move. The reticle is now optically centred.

A couple of times (to satisfy my curiosity), I've then counted clicks in each direction to see how far off the mechanical and optical centres are.

So far, the mehcanical centres of 3 Leupold and 2 Bausch & Lomb scopes have been within about 2 MOA of the optical centre. So, for at least these 5 scopes, I think there would be little difference in subsequent performance.

I have no idea how well these results might apply to other brands of scopes, or even other Leupolds/Bausch & Lombs!

jpb

That reminds me of holding binoculars pointed directly into the sun while watching the shadow the pair cast. If the two 'noculars are aligned in the same direction, then the light shining through will make perfect round images at the same time.

--
A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

Hey Seafire,Thanks for the Tip. I've done the "V-Groove in the Box Trick" that "jpb" mentioned, but I will try this too.

Just opened the Safe to pull out a scope and try it. Well, the one I was looking for is currently "mounted". (Another Senior moment!) But, it will come off pretty easily (Weaver Mounts) and rezero close enough for now.

Hey Clark, For "Senior Moment #2", I do believe at one time I knew the old Sun Check Trick too, but I'd managed to mentally mis-file it somehow, low batteries, too many brussels sprouts, whatever. Thanks for the "Refresh".