Perfect Every Time Scope Mounting

Thank you very much for such a clear explanation, yes I will be using a sloped base (20MOA). Now I know as well that I need to center the retile at the opticle range. Thanks again.
 
I understand the value in being somewhat centered at a select range. But I'm not quite getting the use in exact centering.

Once your optically centered, how do you determine the resulting zero?
Are you saying that if your centered zero turns out 384yds, or 80yds, that you use this as your zero range?
 
I am guessing that you would rotate the scope at the range you want to be able to shoot at and make sure it is roating in a circle at that range and not eliptically. Again I am guessing as this is all new to me.
 
This exercise of precise centering doesn't sound particularly practical.

And likely isn't necessary but it is what his directions were referring to and does give an exact center baseline for those that may have some OCD issues! :D


Scot E.
 
So how bout my questions w/regard to this perfect setup?
Once you've gone through all this optical centering, with burris ring inserts, what do you have for your zero?
And did US Optics mention turning the scope to set plumb adjustments through the range?
 
By the time a fella got the perfect center for the desired zero range, the screws on the scope rings would be worn out - thread-less... :)
 
Nice explanation Scott.

Finding the optical center is useful when diagnosing the alignment of your barrel/receiver/base. As long as the base is aligned to the rifle bore within +/- 8 moa of the desired alignment (0 bias, -20 moa bias, etc.), you can forget about optical zero. If the base is off more than 8 moa, you should diagnose and correct the alignment problem before proceeding with scope installation.

You will get the best optical performance from your scope if you mount it so that the elevation/windage adjustments are off optical center by no more than 25 moa at the longest range. Off-axis optical aberrations are minimized this way. For long range shooters that means using a base with negative bias.

As Scott said, Burris Signature rings will cure a lot of alignment problems. Highly recommended.
 
I don't think I was as clear as I should have been in describing the benefits of centering a scope before mounting it. And this is just what works for me guys. I am not trying to say if you do things differently that you don't know what you are doing. Based off my experience this is the best way to get the most out of any scope.

In general, using a scope at its center gives the best optical performance and turret repeatability while keeping the internals in the least amount of stress. A scope that works in a low stress environment at least in theory has a much greater chance of being a more durable and repeatable scope compared to one that is cranked toward its max and expected to hold its zero and provide consistent click adjustment for life. I have personally found this theory to be true in real world usage as well. So these benefits give me the best chance to keep my specific scopes working to their greatest potential. So part of my concept with this is that I am playing the numbers and doing everything I can to ensure that I am setting up the scope as perfectly as possible so it can do its job as well as possible over the longest period of time before failure.

Similarly, the signature rings aid with this concept because they allow a stress free environment when mounting a scope in rings and bases. Many guys don't realize this but almost always it is your scope that has to give when you have action/base/ring issues that are out of spec causing improper alignment. So in an example with a misalignment issue, with traditional rings you end up bending or torquing the scope tube in order to try to get in clamped down and aimed in the proper direction. This causes issues with all of the internals working correctly so before you even get to the centering of turrets concept, you have already induced stress in optical performance, turret repeatability and durability. Then add a scope that is trying to work on the edges of its turret adjustment and you can begin to see these little things turning into big things over time. Also, signature rings make it much more difficult to crush a scope with too much ring torque which puts stress on the internals as well. It should be noted that rifles with properly aligned mounting screw holes and straight bases and well machined rings will eliminate most of this issue as well so I am not making any such claim that the signature rings are the only way to skin this cat. But there are a lot of rifles that don't have all of this stuff lined up and there are a lot of guys that can't afford to get it fixed or can't afford to buy the best bases and high end machined rings and a really cheap and really effective way of handling it is to just use the signature rings. They are fantastic!

For years manufacturers have claimed that they believe around 60-70% of scope failures are due to improper mounting of a scope. A lot of guys poo poo this idea thinking it is just an excuse but once you begin to see these things at work I don't doubt that they are at least on the right track most of the time. I have seen all kinds of issues with scopes in traditional rings that are completely eliminated with signature rings. Things like the power ring having heavy spots in certain areas when adjusting power, to parallax turret or AO not working or working sporadically, to turrets not being repeatable or running out of adjustment quicker than they are supposed to. I have done a ton of testing on turret repeatability and click values as elevation reaches its max with scopes that are mounted vs not mounted and you would be amazed at the difference in some of those tests! Yes, the better made scopes do better in this regard but even they show effects and in some cases the big brand names are much worse than some of the mid level models.

So in a bit more detail, the concept of centering your turrets, whether you go to the extra effort of optically centering them or just getting close with a click count, is to get your turrets centered so you have a basic understanding that you have equal movement in all directions if needed. This is the location everything will work at its optimum level with the least amount of stress on internal components. The lenses are lined up perfectly so you theoretically get the best picture, read as most clarity, brightness, and resolution, while eliminating the most amount of issues, ie, CA, vignetting/tunneling, turret and parallax issues, lessened eye relief, more critical eye box, etc.

So the benefit of the Burris rings are that you can set your scope up to near perfect and then adjust the ring inserts to get you zeroed in at whatever distance you want. For me that is usually 200 yards. So I can bore sight or use whatever method I want to get POI and POA to match up but for this initial step I am only adjusting the ring inserts to get this initial stage completed. I personally throw my rifles in a lockable rest, pull the bolt, and perfectly center the target through the barrel. I then begin rotating the ring inserts until I get my reticle as close as I can to center of the target. I tighten the rings, take a shot and measure the distance I was off of center. Most times I can loosen the rings, taking care to keep track of where the inserts where positioned, and fine tune the inserts to get me even closer. Then I tighten back up, verify with another shot and then I am done with my initial zeroing.

Of course there is going to be some minor usage of the turret adjustment to get perfectly centered at your zero point. I think this is where I confused some folks. But the amount of adjustment needed to do this is very small, often times only a couple MOA, so I am still very close to centered up which is ideal. There is obviously a range of movement around the center where you loose little performance optically or mechanically speaking and the signature rings and beginning with a properly centered scope allows you to stay in this area as much as possible. I personally try to stay out of the top and bottom 1/4's of the adjustment range for all of my shooting. I feel this gives me an amount of adjustment that is very dependable and repeatable. Depending on my use and the specific scope I have this may or may not always work but I usually can get very close with this system. Some scopes can go further towards the extremes of turret adjustment and some can't. One of the reasons you should test every scope or in my mind play it safe and use this system, or one similar, so you give yourself the best chance to keep things repeatable.

Now a LR guy may not want to set up his scope to be centered at 200 yards because he mostly shoots at say 600-1000 yards. So he may want the best optical and turret performance at those distances. Plus he may need more elevation adjustment to get out to the farthest distances he shoots. This is still easily done with this system. With a centered scope, or if needed with a scope adjusted lower so you have more up elevation, you can then use the inserts in the same way you would use a sloped/canted base and can at the same time still use the inserts to get you on target if there are alignment issues on the windage plane.

Not sure if I have better explained or muddied the waters further! :)

Scot E.
 
I have an SN 3 from US Optics, yet to mount it. Instructions say to first center the erectors, ok no problem, then says to rotate the scope 360* to make sure reticle is not ellipticle,while aiming at 100 yd target, if ellipticle, use elevation and windage knobs to bring retical to perfect circle. Is any one familiar w/ this procedure ? If so could you expand on this some more ?

No way I could rotate my rifle scopes 360* in their rings with one-piece base setups, unless I cut the turrets off the scope tube. My turrets won't clear the one-piece bases beneath the scope tube. If I understand what's being proposed, this isn't even possible with any of my LRH rifles.

Edit: the parallax adjustment wouldn't even clear the base, let alone the turrets.
 
No way I could rotate my rifle scopes 360* in their rings with one-piece base setups, unless I cut the turrets off the scope tube. My turrets won't clear the one-piece bases beneath the scope tube. If I understand what's being proposed, this isn't even possible with any of my LRH rifles.

Edit: the parallax adjustment wouldn't even clear the base, let alone the turrets.

Ya, that is to be done off the rifle.


Scot E.
 
This is a thread for discussion of the article, Perfect Every Time Scope Mounting, By Darrell Holland. Here you can ask questions or make comments about the article.


LOWLY CANUCK WONDERING WHERE TO PURCHASE THIS SETUP...

Mr. Hollands site states only sells to USA. gun)

We have nice guns up here in Canada too. Please if anyone knows of someone selling to Canada or in Canada, let me know where.

Thanks I enjoy your stories on LRH site.
 
This is a very useful thread and just happens to have the info I'm looking for! This of course thrills me! Up until I've gotten into long range shooting which for where I live isn't very far 1-400yds. I just recently fond a 600yd range but its about an hour away and private. Anyway I never paid any thought to all of this but now it kinda troubles me as I think upon all my rifles and how all of them except maybe one needs to have this done! I can't thank you guys enough for the input and tips and this thread in general! My biggest object now is to get this equipment and start remounting my scopes. If you guys can think of anything that would help me and make the process more simple please feel free to point it out.
 
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