Discussion in 'Technical Articles - Discussion' started by ADMIN, Nov 12, 2011.

Perfect Every Time Scope Mounting

  1. ADMIN

    ADMIN Administrator

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    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.
     
  2. Mikecr

    Mikecr Well-Known Member

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    While this is often a good enough approach, it is not always the best approach.
    For one, reticle alignment with the shooting plane is only useful to those who hold-off using their reticles. For those of us who dial, we might not even use a crosshair type reticle, but a simple dot instead. In any case, the 'dialers' need to set the elevation ADJUSTMENT plumb to the world regardless of any reticle cant.

    It's a bit tougher to do in the living room. And you really need to set a 'Scoplevel' (the original) on this. But it's only one extra step beyond described procedure.
    At a 100yd range hang a plumbline. Clamp or hold solid the gun, or the scope alone, at what you think is level while aimed at the bottom of the line. Get someone else to carefully dial the elevation turret many moa upward & then check your aim. Loosen the rings for mounted scope & turn the intersection(center POA) back onto the line. Set the Scoplevel. Repeat going downward & adjust, back & forth until it's always right.

    With this, your elevation adjustment is always indicated by the Scoplevel, even when moving the scope from gun to gun or left on a shelf in a safe. In other words, you don't have to do this again with that scope on another gun, and gun cant itself doesn't really matter.
    I shoot a T2K at 7deg cant.

    If the crosshair is factory set plumb with the adjustments, that's great. Sometimes it turns out that this isn't the case. Doesn't matter to dialers.
     

  3. pyroducksx3

    pyroducksx3 Well-Known Member

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    Are these scope base "adjustment screws" proprietary to hallands bases? I have nightforce bases and dont believe this to be an option. Is leveling the base even necessary? If the rifle is held level by the clamp then cant I just use the plum and level the reticle to that? Thank you
     
  4. phorwath

    phorwath Well-Known Member

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    One step I include that I didn't see mentioned. I place a 4 foot level or any other straight edge along the scope base (or bases if two piece) to ensure the scope bases are in alignment with the barreled action. I am ensuring that the straight edge has the same amount of offset - left to right - from the center line of the bore at the muzzle, prior to securing the scope base to the rifle receiver. I had one receiver where the one-piece base was pointed cattywompus. I had to use a Dremel tool to enlarge the sides of the screw mounting holes in the base in order to align the base to the bore of the rifle. Only then was the scope base able to be mounted parallel to, and in left-right alignment with, the bore at the muzzle.

    In addition, I use a 'Vertical Reticle Instrument' manufactured by EXD Engineering. I purchased mine through Brownells. Part number 289-100-000
    EXD ENGINEERING VERTICAL RETICLE INSTRUMENT - Brownells

    This tool helps to ensure that the center-line of the scope is positioned directly over the center-line of the bore, at the same time the scope reticle is turned to vertical with the plumb bob string. I try to set my plumb bob up 50 or more yards from the scope. It just seems easier to see the plumb bob string. This tool rest on the barrel and the objective end of the scope tube - concurrently, and then the user tilts the rifle until the bubble level indicates the scope tube and barrel are plumb with the earth. After this is achieved, the scope is turned in the rings until the crosshair is vertical with the plumb bob string, at which point the ring screws are snugged down (while ensuring alignment with the plumb bob string is maintained). And then finally, an anti-cant scope level device is mounted while everything is confirmed to be properly aligned - parallel with gravity.

    This method works slicker than snot. And provides high assurance of a correctly mounted scope.
     
    Last edited: Nov 28, 2011
  5. Gary Kaney

    Gary Kaney Well-Known Member

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    I bought one of those from Brownells. It's the best 45.00 i ever spent. As said IT WORKS SLICKER THAN SNOT.
     
  6. etisll40

    etisll40 Well-Known Member

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    If your scope is accurate at 100 will it be at 1000?
     
    Last edited: Nov 29, 2011
  7. Mikecr

    Mikecr Well-Known Member

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    etisll40, you are changing the subject of this thread...
    Should start another
     
    Last edited: Nov 30, 2011
  8. jagsr71

    jagsr71 Member

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    Just curious if the frame of an AR can be accommodated in this fixure or if it's more suited for a standard rifle?
     
  9. marksman3006

    marksman3006 Member

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    One thing to try is to zero your scope and then dial it up and with the reticle again on zero the new group should hit above but not left or right. This will let you know if the scope is canted.
     
  10. lobster

    lobster Active Member

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    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 elipticle,while aiming at 100 yd target, if elipticle, use elevation and windage knobs to bring retical to perfect circle. Is any one familiar w/ this proceedure ? If so could you expand on this some more ?
     
  11. Mikecr

    Mikecr Well-Known Member

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    Sounds like a test US Optics would do themselves. After all, your scope zero won't ever be optically centered.
     
  12. Scot E

    Scot E Well-Known Member

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    Centering the erectors/turrets, is a way to get you close to optical center and is typically done by counting clicks from the top of the turret adjustment to the bottom then dividing that number by 2 to get your basic starting point. Do that for elevation and windage and you should be close. Rotating the scope 360* and watching the reticle is their way of fine tuning to a perfect optical center. When you rotate the scope, if you are off center the reticle will appear to move around in an oval in relation to the target until you adjust the turrets and find optical center.

    A small cardboard box with weight in the bottom and v cutouts to hold the scope will allow you to turn the scope consistently while looking at the reticle-to-target relationship.

    This process is important because it helps you make sure your scope to bore alinement is correct. There are a number of things that can mess up proper alignment like receiver issues, base misalignment caused from improperly drilled holes, crooked bases or rings, etc. knowing the proper starting point is important to making sure you are setup correctly in the end. But keep in mind mounting your scope optically centered is usually only done for traditional shooting at closer ranges which would be on a flat base. Most LR guys end up using a sloped/canted base or rings to ensure their scope works properly at the distances they shoot and to make sure they have enough elevation to shoot LR. If you are going to be using a sloped base your adjustments may change but at least you know where center is so you can adjust things to your desire.

    Many shooters like their scope to be optically centered at the distance where most of their shooting is done so for LR range guys that is maybe 600-1000 yards. This is because the scope is optically the best when centered so optical aberrations are limited giving the shooter the best view of the target at the distances that are most critical. Also as a turrets reaches its max adjustment it can begin to lose consistency or change in adjustment per click or stop working all together (especially if say the elevation is close to max and then the windage turret is used). So by using a sloped base or adjustable rings like the Burris signatures you can pretty much set up your scope to run as well as possible and have the least chance for error at the longer shots where the real necessity for accuracy is at.

    I really like the Burris signature rings for setting up a scope correctly. They really spoil a guy after using them. They really are the slickest concept I have ever seen. The adjustable inserts allow you to get almost perfect scope to bore alignment and cant (if needed) without using any internal scope adjustment. It is all done with the inserts. Then you know that your scope can be adjusted from its center which gives it the best chance to work as designed. The rings also grip better than many standard rings, leave the scope in a near zero pressure environment (unlike some rings that are misaligned and end up bending the scope when the rings are tightened, and never leave ring marks on your scope. There are more ways to accomplish this but nothing I have seen that is as easy, cheap, and that works so well.

    HTH,


    Scot E.
     
  13. etisll40

    etisll40 Well-Known Member

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    Great insight and knowledge Scott. Thanks for taking the time to write about this, I learned something about scope alignment that I never was comfortable with and this does explain it.

    I probably will buy some Burris signature rings as them seemed interesting and a good idea when I read the review on here. A friend and a good gunsmith and benchshooter suggested them as a possibility but I decided on nightforce rings on the 7mm stw he built for me. Can they take the pounding and still not break or un torque?

    Another question about the Burris rings and others? What torque setting should a scope be set at to not damage the scope and along the same lines, what torque for either the rings and/or a rail too. Should locktight be used with any of these?

    Thanks,
    Ed
     
  14. Scot E

    Scot E Well-Known Member

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    Regarding their ability to hold on the magnums, this is what I can tell you. I have read some threads about them not holding with the really big magnums but when I or someone else inquires about the specifics it almost always ends up being something like, "well I have never tried them on the magnum cartridges because I just don't trust the inserts to hold." Not exactly good science!

    I know guys that have them on their edges, 300 and 338 Win Mags, and other similar cartridges and have had no issues. I have had 100% success with them on that level or recoil and below. I have also used them on precision airguns which have much worse recoil than any centerfire and they work fine. So I would say your will be fine.

    Torque ratings are base and ring specific so read the directions that come with your bases and rings. I always locktite bases and almost always locktite rings but do so with a less permanent solution in case I need to remove the scope.

    Scot E.