If you shim or have tilted scope bases

Forums Optics, Scopes, Rings, & Mounts If you shim or have tilted scope bases

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    Haganaga
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    I was looking up scope tracking and on some of the long range power burner forums there were a couple people who repair scopes and they said a majority of the repairs are the internals of the scope when they’ve cranked the scope all the way down to zero their scopes at -20 to -30 moa. THE PROBLEM IS they leave them there and the springs set or break altogether. Which results in crappy tracking as you can imagine. They recommend, and it makes sense, to return the reticle to neutral to store it. Then rotate to zero for the shooting session. FYI

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    Shinyknight
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    On my mtc viper pro. I used adjustable mounts but I still crank my turret all the way down and leave it as my zero. That way I have the whole range to dial back up giving me longest distance possible. I watch Ted's video on it and he said when mtc built it, they know about scopes being dial all the way down or up can damage the scope. But they purposely made the mtc scope able to dial down without damaging it. That's how I set my scope and it still hold zero at each yard I set it to.

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    Haganaga
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    Gotcha, but for the owners of everything except mtc, it may be good to store them in neutral.

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    Bob_O
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    Doesn't sound like a bad idea Hagnaga.

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    JamesD.
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    Shinyknight

    On my mtc viper pro. I used adjustable mounts but I still crank my turret all the way down and leave it as my zero. That way I have the whole range to dial back up giving me longest distance possible. I watch Ted's video on it and he said when mtc built it, they know about scopes being dial all the way down or up can damage the scope. But they purposely made the mtc scope able to dial down without damaging it. That's how I set my scope and it still hold zero at each yard I set it to.

    Very good to know. I’ll check MTC out. Thanks!

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    Skip-in-WV
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    Which way stretches the spring? All the way up, or all the way down?

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    nervoustrig
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    Firstly, note erector springs are compression springs, not extension springs, so the force acting on it is one that collapses it rather than stretching it.

    Generally, dialing the elevation turret all the way clockwise will compress the spring maximally.

     

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    Eamon
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    Skip-in-WV

    Which way stretches the spring? All the way up, or all the way down?

    Both, My contacts at Vortex assures me that is best do it DIY way to wreck a scope. Followed by shims as you put the scope tube under undue stress. You can tweak it enough to hurt the gears without being able to see it yourself.

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    nervoustrig
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    Please explain how it occurs in both directions.  Even if we substitute the word “stressed” in place of “compressed”, I don’t follow that statement.  

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    DuncanHynes
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    Never shim 2 separated mounts.  Shim the entire base itself or a one piece under itself.

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    Haganaga
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    Skip, either way, up or down. It’s the long term compression that creates “spring-set” where it doesn’t expand with the original force. This leads to, from what I’ve read, is tracking issues or clicks not being uniform. And dammit, I’m on vacation and can’t get to my scopes for a few days. Can anybody swing by my house real quick and center all my scopes???!!!

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    Bob_O
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    I centered mine before heading out for work if that helps you feel better.  

    🤣

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    Haganaga
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    Yeah, so much better 😭

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    shoot44
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    Self defense guys have known for a long time to spend more than you can afford for magazines you keep fully loaded and will never use, just in case. Some use specially rated springs for this task but are not cheap. Bet you anything what you describe is less likely to happen to a $2000 scope then a $500 one. Some of that unseen quality you pay for.

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    Haganaga
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    Yes, exactly. Which is why I rotate magazines and buy replacement springs. But I didn’t even think about this factor in scopes till I read that from a couple scope repairmen in another forum. Might prevent breakage or tracking issues on those cheaper scopes.

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    Haganaga
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    Let me ask this. Should I rotate the scopes to the opposite extreme and leave it for a few days to re set the springs? 

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    Motorhead
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    This is silly …. Springs are designed to be be SPRINGS and therefor compressed or relaxed they have memory.

    We're NOT TALKING as if a scopes internal erector springs are being violently cycled such as spring piston gun beats up there spring, but very gently moving incremental distances doing IMO no damage to the spring what so ever.

     

    I see this as YELLING fire with someone lights a match …. JMO tho.

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    nervoustrig
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    ^ This.

    There is perhaps some merit to avoiding running the turrets to the very extremes.  A well designed scope won't care but a cheapie may not like it.  At the extreme where the spring is most relaxed, the erector tube may not have sufficient pressure to keep it stationary  against the turrets which could cause the zero to wander as it settles into a new location after each shot.

    At the other extreme where the spring is perhaps fully compressed, it's possible that the erector tube experiences a greater transfer of recoil and therefore may contribute to a premature failure (e.g. a reticle that breaks or begins to rotate).

    However there's no reason to be concerned about an erector spring staying at, say, as much as 90% of its travel for extended periods of time.  Like Scott said, it lives a rather mundane life.  Springs fail chiefly due to work hardening from cycling back and forth.  A spring that loses its ability to maintain tension while just sitting still…well, it wasn't much of a spring to begin with.

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    airgunfans
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    Eamon

    …. shims…. put the scope tube under undue stress. 

    My practice is centering the recticle first by the "V-block method", ie, put the scope on a pair of  V-blocks so that the scope can be rotated along it's optical axis, adjust the knobs until the center of the recticle stays in the same spot no matter how the scope is rotated.  Then zero the scope by shimming.   The material I used for shimming is fiber glass cloth and epoxy resin so the shim is effectively molded to fit the ring and the tube of the scope perfectly, there is no stress at all. 

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    bandg
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    I don't shim rings/bases but I've often thought that if someone needed to do it then something like you mention would be the way to reduce/eliminate stress.  Bedding compound or even JBWeld might work but the FG cloth and resin seems like a very good idea.  Do you use any type of thin or small spacer to set the scope soundly onto before making the final spacer?  I assume you do this to both top and bottom of front and rear rings?  Lube on scope to prevent sticking?

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