How do you center scope with mirror?

[glassman98]

How do you center scope with mirror? Did a search with no results. Craig

[BenjiHunter]

Put the scope up against a mirror ( a bathroom mirror works). Look thru it and you will see one or two reticles.
Turn the knobs until the two reticles come together.

[glassman98]

Thanks Stefan.   Craig

[shooter r]

I've never tried that but I would still put the scope on a set of "V" blocks, just to check it. With the magnification set high, you align the crosshairs on a distant object, then slowly rotate the scope. If the scope is "centered" the crosshairs will not leave the target. Until you've done it a few ties, it's trial and error which way the turrets are turned to adjust it to centered. You can use a small box with 2 notches cut in them for the blocks. Add a few cans of pellets to weight it down a bit.

[nervoustrigger]

3 methods for centering a scope
https://www.gatewaytoairguns.org/GTA/index.php?topic=116903

[elh0102]

Put the scope up against a mirror ( a bathroom mirror works). Look thru it and you will see one or two reticles.
Turn the knobs until the two reticles come together.

This method works, but I believe that either using a V block, or counting clicks, is a bit more accurate. But, it doesn't need to be perfect, just close to the scope's mechanical center. If using a mirror, it helps to set the power to its lowest setting, and the AO at infinity.

[jus Tom]

I've used the mirror method ever since reading about it on this site years ago. Certainly the other methods work also and may be better for proving exact center. But I believe the main reason,, at least for me, was to keep the internal adjustments in a more stress-free condition when using the scope on a dual-direction recoiling spring gun.
Now on "some scopes"....(RWS factory supplied, Hawke Airmax EV and likely others) stress-free centered didn't matter....reticles still rotated or crosshairs broke.....nature of the beast-ly gun . 
I've gotten into the habit of using a laser-scope-tool in the barrel at first mounting of the centered scope to see where it points compared to crosshairs. Then, if barrel droop is noticed, I'll be shimming my rear rings slightly to allow my scope to be adjusted as close to center as possible at final zeroing.

[bavaria55n]

I am disappointed. Thought this was going to be how to look in a mirror to sight your gun backwards over your shoulder.
Gary

[lefteyeshot]

I just turn the adjustment knobs one way till they stop. Then count half turns till it stops at the other end. Then half that many half turns back. If it's say 12 half turns from far right to far left or top to bottom, then 6 half turns back. Why half turns? That's the easiest most natural way. My wrist want rotate 360 degrees. That's close enough to center you need to be to re-zero.

[cosmic]

Mirror method even easier If you have a illuminated reticle turned on..

[rsterne]

The mirror method will not work if you have a scope where the front of the objective lense is not perpendicular to the centerline of the scope.... Some side focus scopes have a built in "half sunshade" where the front is on a steep angle, and that obviously won't work.... Some AO scopes may have a slight misalignment of the AO bell, due to improper machining or threading, which is not obvious.... but even a slight angle to the front of the objective will give incorrect results using the mirror method for optical centering....

The most accurate method for optical centering is to use V blocks.... but I use simply counting clicks (actually revolutions) from one end to the other and then come back halfway to center the reticle mechanically.... That puts you close enough, and in 99% of cases you have to adjust off center a bit anyways to sight in the rifle.... The only way to keep the reticle optically centered and sight in the rifle is to use adjustable rings to sight it in.... In most cases that is not necessary, but if you center the scope optically (or mechanically) and then find that to sight the rifle in you have to adjust wayyyyyyyy off center.... then you know you have an alignment problem between scope and barrel....

If you are sighting in for long range, for example 100 yards, then you would be well advised to use a set of 25 MOA scope shims like those made by Hawke.... This will put you close to optical center while likely dropping the pellets on the paper at that distance.... Some guns, like the Slayer, already have the scope dovetails at an angle to the barrel, IIRC they have about 20 MOA machined right into the receiver....

Bob

[Springrrrr]

Centering a scope is fun, then you mount it on the rifle and twist away on the knobs to get the gun on target.  I hardly makes sense to do it UNLESS you have adjustable mounts that allow you to keep the scopes controls where they were centered and move the mount knobs to get on target.

Then if you make minor corrections using the scope knobs, you can be sure that up is up and left and right are just that, otherwise, moving the controls, if the scope was not left at center point, may move things on a slope not perfectly horizontal or vertical.

Here is one example of the type of mount of which I speak.

http://www.airguns.net/reviews_sportsmatch_adj_mnt.php