Sako Scope rings sliding forward during recoil

Discussion in 'General Sako Discussions' started by Bernie’s Dad, Aug 8, 2021.

  1. Bernie’s Dad

    Bernie’s Dad Well-Known Member

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    These are brand spanking New Old Stock. They were sealed in plastic and covered with oil. I set the front mount flush with back of dovetail. It moved a few mm after a day at the range. I am guessing there is still too much oil in the screws? Not malfunctioning?

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  2. stonecreek

    stonecreek SCC Secretary Forum Owner SCC Board Member

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    If the rear ringmount is brand new then it will have the indexing lug on it and can't move forward. This would mean that the scope had to slip inside the rings as well as the front mount move on the dovetail. This would indicate that neither the ring cap screws nor the dovetail clamps were tight enough. BTW, the insides of the rings should be completely dry with no oil so that they will clamp securely on the scope. Are you sure that the rings are 25.4mm (1") and not 26mm?
     
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  3. Bernie’s Dad

    Bernie’s Dad Well-Known Member

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    Receipt says 25.4. There is room to tighten. I’ll dry them better and tighten more. Thanks. (I am always afraid to over tighten)


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  4. Bernie’s Dad

    Bernie’s Dad Well-Known Member

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    Front thumb screw would have had to give a little too, right?


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  5. Old Hippie

    Old Hippie Formerly known as bloorooster

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    Daddy-o
    Try this..it was taught to me by an old mentor of my youth.
    Hand torque..or as some say the torque wrench in the elbow, can be controlled by how many fingers one uses to grip the driver handle and tighten the screw. One finger, along with the thumb of course, will grip tight enough to apply small amounts of torque, while 2 fingers will apply more, but not as much as 3 fingers. A full fisted grip using all available digits will be the heaviest…until the other hand must be used for even more torque.
    On my scopes rings I use one finger tight never more than two. This means as tight as one can physically turn the screw without adding another finger to the grip…are you with me? Hang in there!
    Scope rings and thumb screws - 1-2 fingers
    Butt plate screws - 1-2 fingers
    Action screws-front recoil - 4 fingers- rear tang - 2-3 fingers .
    Try it and see, or fuss around till you find a torque driver from Midway USA or similar.
    Use the proper driver tips always , hollow ground blades of the correct fitting width or as close as possible.
    Test the theory on a 2x4 with various screws to get a feel for what I’ve explained. It takes some control and some finesse but not hard to comprehend the application.

    The Hippie
     
  6. Bernie’s Dad

    Bernie’s Dad Well-Known Member

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    Thanks. I will. It’s the scope rings that are moving up the dovetail, right? So that means the thumb screw on the right is allowing it? The ones on the left have clicks? So I need to tighten the right thumb screw more not necessarily the top screws? Could there be oil in those threads from the way it was packed?


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  7. Old Hippie

    Old Hippie Formerly known as bloorooster

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    I don’t think oil is the problem, the rings are just loose. I have removed and installed many , many sets of scope rings and I don’t think I’ve ever seen a set that didn’t have a film of gun oil between mating surfaces.
     
    Last edited: Aug 10, 2021
  8. stonecreek

    stonecreek SCC Secretary Forum Owner SCC Board Member

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    The rings should be stamped "25.4" on the bottom.

    You are correct to be cautious about over-tightening the cap screws since they can easily be broken with just elbow power (take it from someone who knows :(). Get them nice and snug by rotating back and forth among the four screws on each ring so that no single screw is holding more tension than its mates.

    Although some will argue that hand tightening is adequate for RH the thumb nuts (and yes, do not tighten with the LH indexed nuts), I judiciously use a screwdriver with a split blade to get the nuts just a bit tighter than hand-tight. I have seen rings warped by over-tightening the thumb nuts with some kind of tool.

    There is no problem with the screws having oil on them -- in fact they should have some very light lubricant. But you want the claws that grip the dovetails and the inside surfaces of the two ring halves to be completely dry. A gloss finished scope will slip in the rings much more easily than a matte finished one, so when mounting a gloss finish this is especially important.
     
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  9. sempreelk

    sempreelk Active Member

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    I read an old factory Sako scope ring mounting instructions yesterday and they say to use scotch tape inside the rings to avoid marks. I would copy it and post it here but I would be using someone else's content.
     
  10. Bernie’s Dad

    Bernie’s Dad Well-Known Member

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    Seems logical.


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  11. Bernie’s Dad

    Bernie’s Dad Well-Known Member

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    Seems logical.


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  12. South Pender

    South Pender Well-Known Member

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    Two observations:

    1. Make absolutely certain that there is no oil on the inside of the rings, I go one step further by applying a dusting of rosin to the inside of the dry rings. This facilitates inertia, and I've never had scope move in the rings even with heavy-recoiling rifles.

    2. If you have a torque screwdriver, tighten the ring screws (with very lightly-lubricated threads) to between 15 and 20 in.-lbs., employing the back-and-forth procedure outlined above by stonecreek.

    If you do 1. and 2. (and in fact these are 1" or 25.4 mm. rings), I can't imagine a scope slipping in the rings
     
  13. Bernie’s Dad

    Bernie’s Dad Well-Known Member

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