Air Gun Home :: View topic

dummyracer36 · Senior Member

ok, i have read too many methods for "optically centering" a new scope... can some please explain it to me in a manner that a dummy can comprehend?

Slavia · Moderator

The back wheel on your motorcycle is mounted crooked, but you can move the handlebars enough to get it to steer straight. Or maybe not, if it is really crooked. Better to mount the wheel so it wants to roll to the same place as the front.

Or - your wife is helping you wrestle that freshly painted corner cabinet into the kitchen (the one she started and then dumped in your lap). Only she isn't pushing in the same direction that you're pulling. In this case there are no adjustments possible, so replacement is better - get the son.

Still confused? This is probably better:
http://www.pyramydair.com/blog/2005/07/how-to-optically-center-scope.html

Rogerflat · Silver Status Member

It's easy. Take a ruler or protractor or whatever, and draw a perfect cross on a sheet of paper with a sharpie. It should look just like your crosshairs in your scope. Now, tape it to a wall and set up about ten yards or so away from it. Take a level and make sue that the horizontal line on the sheet is parrelel (level) to the ground. If it's not, adjust the paper accordingly and re-tape it. You know the vertical line will be veritcal if the horizontal one is set correctly because you already made the cross at a perfect 90 degrees with your protractor.

Now, mount your scope but so it can still be turned with your hand. Look through it and line up the crosshair with its mirror image on the paper. You also want to make sure that your rifle is level when you look through the scope. Use your level again for this.

billandbeaufort · Senior Member

Rogerflat · Silver Status Member

Oh, that's right. Good point. And a good way to center it as well.

dummyracer36 · Senior Member

ok, using bill's method, how far away from the wall should i be? and i assume the scope needs to be "dead on straight" to the wall, or error will occur?

cw · Banned

There is a way easier method. Put a piece of glass on a mirror.
Then put the objective bell of the scope on top of that. If the scope is
not optically centered you will see a double image of the reticle
(crosshairs). Adjust the turrets untill the two images come together.
Your scope will now be perfectly optically centered.

I can't take credit for this method as my Sec Op father taught it
to me.

AirGunEric · Site Admin

CW:

I'm having an issue understanding what you're saying- lay a piece of glass flat on top of a mirror, put the objective end of the scope on the glass, look through the top to make sure there is no double image(?) And enough light will get through the mirror/glass to be able to see the crosshairs- or do you have to have some sort of lightsource pointing right at the mirror/glass near where the bell is placed?

kanyon · Silver Status Member

Dam..After reading all these ways to mount a scope. The way I do it is so simple it can't be RIGHT...My guns are only able to head shot a bunny at 50m..If I use some of these ways I maybe able to de flea them first.
All I do is bolt the dam thing on line the cross hairs up vert/hor & get the eye releaf right for you.Then go out and start shooting til you can hit what you want at the range you want. This way may "NOT" be right but it works have heaps of bunny carcases to prove it. If you are into putting holes in cardbord you would prob need to use one of the other ways to get the 1mm groups that targets shooters like.

dummyracer36 · Senior Member

ok i tried the mirror and glass method last night, and i think i got it. now that the scope is centered, to take advantage of this, do i need adjustable mounts? seems to me that i would, or all the work of centering the scope to begin with would be for not as soon as i undid it all by sighting in.

cw · Banned

Eric, yes, you want a low, indirect, subtle light source.

I've done it both ways, the above way and rotating the scope
in a v-block. They both work great, but the mirror way is a little
easier and quicker for me.