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Bob1949
01-26-2018, 02:43 PM
I recently received my new target dot scope and as I marveled at its optical wizardry, I wondered: How can I tell if the reticle is optically centered on the center- line of the scope tube? Has anyone on the forum given this any thought?

Bob

blades
01-26-2018, 03:22 PM
simple way put a dot on mirror , make a support for scope from a box so that you can freely rotate scope look through scope align crosshairs with dot on mirror rotate scope while looking at dot through scope if it stays on dot is centered

Bob1949
01-26-2018, 03:44 PM
Blades,
The technique you describe sounds interesting. I have read about a method using a mirror but it described adjusting the reticle until it and its shadow merged. I appreciate your response.

Bob

Boyd Allen
01-26-2018, 03:58 PM
I have a wood (overlaid with masking tape) V block setup that is designed to mount on a camera tripod. After adjusting the tripod and mounting the tool I place the scope in the Vs and adjust the windage and elevation turrets until the intersection of the cross hairs does not move relative to some fixed object in the distance. Learning how to do this takes a little figuring out, but once you have it goes fairly quickly. I first work with the vertical cross hair noting where it is on the "target" and then flipping the scope over half a turn and noting the difference. Then I adjust out half of that distance with the windage turret and repeat until the line does not move. Then I turn the scope a quarter turn and do the same thing again, adjusting with the elevation turret. When I have finished I can roll the scope in the Vs and the center of the reticle does not move.

Bob1949
01-26-2018, 04:30 PM
Boyd,
The method you use, I assume, will require the target to be within the scope focus range. It seems like something thatís simple to construct and can be used to check a scope. Thanks

Bob

Boyd Allen
01-26-2018, 04:37 PM
Yes, if you are going to really split hairs you do not want to have any parallax. On a semi-related matter I have figured out what sort of auxiliary lens it takes to make a scope parallax free with a sharp image at a distance of about 12.5'.

tim
01-26-2018, 07:42 PM
Bob,
You bought a new scope....it's centered or damned close.
Mount it, shoot it, and concern yourself less with internet solutions in search of problems.
This is required pretty much only if you're remounting a scope on multiple rifles, even then, with custom CNC componants, I cannot remember remounting a scope that was off by more than a few clicks.

Boyd Allen
01-26-2018, 11:15 PM
Tim, He asked how to do something and I told him. We both answered on the Internet, so I guess that both of our posts are internet answers. For many of us, curiosity is enough of a reason. Certainly none of us need permission for that.

John Kielly
01-27-2018, 12:18 AM
it's centered or damned close
... unless a noname like the one who screwed the elevation full down & the windage full right & left it like that on a new scope that I later bought happens to cross your path. Wouldn't track worth a damn & had to be returned & replaced.

tim
01-27-2018, 03:50 PM
... unless a noname like the one who screwed the elevation full down & the windage full right & left it like that on a new scope that I later bought happens to cross your path. Wouldn't track worth a damn & had to be returned & replaced.

Did he not say it was new? You ever hear of a new scope turned full in any direction ?

tim
01-27-2018, 03:53 PM
Tim, He asked how to do something and I told him. We both answered on the Internet, so I guess that both of our posts are internet answers. For many of us, curiosity is enough of a reason. Certainly none of us need permission for that.

The internet is a wonderful thing, you often can get answers to anything. It never does seem to help understanding what questions need answering in the first place.

Boyd Allen
01-27-2018, 04:04 PM
Of course that would be entirely up to the person doing the asking. This sort of reminds me of someone asking how many guns a person needs to own.

Bob1949
01-27-2018, 04:16 PM
Tim,
The reason I asked the question is I wanted to check my used scopes. The thought was to center them all and put them in the cupboard. The scope Iím putting away has a tactical reticle, the new one has a target dot with fine lines. Iím hoping it will improve my attempts to hit something. I have gathered a lot of information on this thread and want to thank all for the help.

Bob

John Kielly
01-27-2018, 04:23 PM
Did he not say it was new? You ever hear of a new scope turned full in any direction ?
This was new, on the stand at the gun shop.

alinwa
02-04-2018, 01:57 PM
Tim,
The reason I asked the question is I wanted to check my used scopes. The thought was to center them all and put them in the cupboard. The scope Iím putting away has a tactical reticle, the new one has a target dot with fine lines. Iím hoping it will improve my attempts to hit something. I have gathered a lot of information on this thread and want to thank all for the help.

Bob

Bob1949, I'm embarrassed.

I'm embarrassed that you feel a need to support your position.

And embarrassed to involve myself in a thread where someone jumps on you for asking a question, ANY question.

But I feel I must.

I teach Hunter Education and Shooting Safety courses and in my opening monologue I make it clear to my students that "THE ONLY STUPID QUESTION IS......"



The one you didn't ask.



So I'm here only to support you and your question, because I despise itinerant preachers.

Bob1949
02-04-2018, 02:33 PM
Hi alinwa,
Let me say that I appreciate your concern. I agree with you that any question is worth asking, even if has been asked countless times before. Iím one of those fellows that are not easily offended and have taken no offense. I only hope I havenít, inadvertently, stepped on anyoneís toes.

Sincerely Bob

alinwa
02-04-2018, 04:15 PM
Hi alinwa,
Let me say that I appreciate your concern. I agree with you that any question is worth asking, even if has been asked countless times before. Iím one of those fellows that are not easily offended and have taken no offense. I only hope I havenít, inadvertently, stepped on anyoneís toes.

Sincerely Bob

In the mean time.......I too have reason to center scopes. And I'll endorse those methods listed which include a vee-block (OR, heresy of heresies!!!) I'll even use the scope rings themselves, rifle firmly bedded or clamped...... Spin thee scope, fiddle a liddle and voilaahhhh, all centered up.

Seriously, rocks on the bank of the backstop, branches on the trees, rifle in the bags.... I've used a piece of cardboard or paper sometimes to crumple into/onto the rings....

(Honestly, I don't understand the mirror method A'tall, but I'm a simply-minded fellow...) And it'll still work, with a dot to look at

Pete Wass
02-04-2018, 11:23 PM
Tim,
The reason I asked the question is I wanted to check my used scopes. The thought was to center them all and put them in the cupboard. The scope Iím putting away has a tactical reticle, the new one has a target dot with fine lines. Iím hoping it will improve my attempts to hit something. I have gathered a lot of information on this thread and want to thank all for the help.

Bob

Everybody gets their turn on here at some point.

Pete

tim
02-05-2018, 11:46 AM
Everybody gets their turn on here at some point.

Pete

Says the guy that brings the spiced wine to the royal table....Dilly Dilly.

glp
02-07-2018, 02:45 PM
Everybody gets their turn on here at some point.

Pete

your dupa is plenty wide enough not to miss an incoming boot!

tim
02-07-2018, 06:09 PM
your dupa is plenty wide enough not to miss an incoming boot!

Hey....what happens in Maine durring the winter, stays in Maine durring the winter.

frey
02-07-2018, 06:47 PM
I'm in the camp that counts clicks from one end to the other, divides by 2 to get the mechanical center.
Then uses a v-block to tweak it from there to the optical center.

I got a wild hair many years ago and wanted to shoot with my scopes as optically centered as reasonably possible.
Did some testing, sort of figured out the bullet drop at 50yds was 7-8" from an optically centered position and had some bases custom milled.
Don't recall exactly, but think the rear base ended up being 17-20 thou taller than the front.
I still ended up having to click a few here and there, but convinced myself I was better off even though it never really showed up in my scores.

glp
02-08-2018, 09:49 AM
I'm in the camp that counts clicks from one end to the other, divides by 2 to get the mechanical center.
Then uses a v-block to tweak it from there to the optical center.

I got a wild hair many years ago and wanted to shoot with my scopes as optically centered as reasonably possible.
Did some testing, sort of figured out the bullet drop at 50yds was 7-8" from an optically centered position and had some bases custom milled.
Don't recall exactly, but think the rear base ended up being 17-20 thou taller than the front.
I still ended up having to click a few here and there, but convinced myself I was better off even though it never really showed up in my scores.

work to get you pretty close. However the suggestion of rotating the scope at parallax distance(if it doesn't allow adjustment) and watching the intersection of the X hairs to see if the image shifts is the best. Tedious but best.

John S
02-08-2018, 12:37 PM
The mirror method has been on the Leupold website for years.

Fred J
02-08-2018, 05:29 PM
John:
Where is that information on their site. I can't find it there.

glp
02-08-2018, 07:28 PM
John:
Where is that information on their site. I can't find it there.

http://rifleopticsworld.com/optically-center-scope/

Pete Wass
02-10-2018, 10:21 AM
your dupa is plenty wide enough not to miss an incoming boot!

They are Googling when they ask a question on here.

Pete

John S
02-10-2018, 11:16 AM
Fred, you are correct the Leupold website has changed. Been a long time since I looked. This subject came up a while back and I referenced it on a similar question and at the time it was still on Leupold's website.

Wilbur
02-10-2018, 03:14 PM
I don't understand why you would want to do this. If somebody knows...please tell me.

Fred J
02-10-2018, 06:22 PM
And not the Underwear, what discipline you might be shooting. For a combo that includes long range, I would prefer that I had enough range in adjustments. Then I would be sure I was centered horizontally and had additional range for vertical.

glp
02-12-2018, 11:26 AM
I don't understand why you would want to do this. If somebody knows...please tell me.

the best clarity, resolution should come at the center of a lens. As you go out toward the edges, where the lens curve is the steepest, you tend to get more distortion and color fringing(chromatic aberration). Just a thought.

Wilbur
02-12-2018, 02:35 PM
I talked to a fellow today that told me you could buy stuff to mount the scope such that it would be "centered" or somewhat close. I knew already that you could center the mounted scope with machine work but didn't know that folks actually did that sort of thing.

glp
02-12-2018, 03:42 PM
I talked to a fellow today that told me you could buy stuff to mount the scope such that it would be "centered" or somewhat close. I knew already that you could center the mounted scope with machine work but didn't know that folks actually did that sort of thing.

I've done it with the finder on my astro scope. However for the last 7 years I've been using one of Bob Brackney's frozen scopes in his rings on my rifle. Love it but wish I had a bit more X. Thinking about an add on magnifier.

alinwa
02-16-2018, 01:25 AM
I talked to a fellow today that told me you could buy stuff to mount the scope such that it would be "centered" or somewhat close. I knew already that you could center the mounted scope with machine work but didn't know that folks actually did that sort of thing.

I build rifles designed for beyond 500yds, out to 1.5mi and using the central axis of the scope is very important to me.

tim
02-19-2018, 08:55 AM
I build rifles designed for beyond 500yds, out to 1.5mi and using the central axis of the scope is very important to me.

Quite useful considering everybody here is shooting at 50, and the OP initially questioned about a NEW scope.
Wilbur.....how many clicks from OEM condition does it take for a match? I'd venture not many.