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rsterne · Moderator

RE the "mirror method", a question and a few comments.... Doesn't it rely on the outside rim of the objective lense being perfectly square with the centerline of the scope?.... I've checked a few scopes to see how square the front is to the tube, and some are good, some are out by quite a bit.... I have one (a $200 scope) where if you put a Machinists square on the front of the Objective and then measure from the square to the tube just in front of the turrets, the difference is about 0.080" (2mm).... To me, that means that the reflection of the crosshairs would not align with the crosshairs by half that amount (eg. 0.040" or 1 mm) over a distance of 7 inches.... Over 100 yards (3600"), that would be 3600/7 = 514mm or about 20".... That would be about 80 clicks off center, by my calculations.... Not only that, but rotating the Objective may or may not cause the reflection to "walk around" in a circle, depending on if the lack of squareness is in the rotating part of the bell or in the threads that it rotates on....

It would seem to me, therefore, that using a mirror to center the crosshairs "optically" may not be the best method.... If the Objective is not square to the tube, I would think that the mirror, likewise, would not reflect the image of the crosshairs straight back down the center of the optical path.... Counting clicks relies on the manufacturer centering the parts in the tube properly, which may or may not be the case.... That leaves us with rotating the scope in vee-blocks bearing as far apart as possible on the tube as likely being the best method, IMO....

Bob

tommytanker · Member

A month or so ago I tried a scope on my old Quest and it did not happen. I adjusted as high as it would go and still was 2 or 3 inches below ctr. I was more interested in HW 50s and did not go further.

Now when you get a Hawke scope they advise running your elevation and windage dials all the way back and then forward and counting clicks. When you find amount of clicks let's say 400 clicks you back up 200 clicks and you have the rough centering of scopes.

Yesterday after doing the count clicks program (first time ever) I remounted scope and I had 195 clicks to play with on elevation. Long story short, after moving elevation up 90 clicks all was good. The last 6 shots were on the button of quarter sized bullseyes and 2 were actually dead ctr. This was only 15 ft but it also was a breezy day. Again I became a legend in my own mind.

Now it's probably the only way I will ever adjust the centering of a scope and I actually thought it was not gonna change anything. No way I understand the mirror stuff and don't believe I have enough years left to accomplish the mirror feat.

Still wondering why scopes don't come new with I guess you would call a rough click centering progam. The good news is now when I get future new scopes I will at least do the click progam.

One last thing does anybody do the tapping of scope dials while adjusting.

Now not trying to advise anybody on methods to use, just explaining my adventure.

One last thing is I have never used any pre-centering method before, I just pull scope out of box mount it and adjust on gun while shooting.

rsterne · Moderator

Counting clicks is not necessary, IMO.... Wind the adjuster all the way to one end, make note of the position of the markings (or slot or raised ridge), and count TURNS all the way to the other end.... They are often roughly 4 turns total adjustment.... Run the adjustmment back the other way half that amount (in this example 2 turns) and you will be as close to optical center as you can get using the "click" method.... If it's 3.4 turns, come back 1.7 turns.... Easy Peasy....

Bob

tommytanker · Member

chet · Member

what we do when i was shooting BR comp. to center the reticle was i made a set of plastic vee blocks, set the scope in it and look thru it at the bulls eye, rotate the scope 90 deg at a time and adjust till when you rotate the scope all the way around the reticle stays in the center of the bull

Chet

Alibert · New Member

...and what if you would have a mirror perfectly perpendicular on your scope rail?

That is, use a spare single scope mount and fix/glue the mirror flat to its side. Then mount the mirror a bit away from the scope to allow light in from sideways, and do the mirror adjustment that way?

Albert.

rsterne · Moderator

If it was perfectly square, that would work.... A couple thou out on the mount and you would get the wrong results....

Bob