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Shimming a scope with pieces of soda can.?
- Thread starter Redick
- Start date
OH, My Veteran rails are at 20 MOA and my Hawke mount inserts are 25 MOA , So I guess I am at 45 MOA? I have the Hawke mount inserts on all my guns, Just saying,
Mike
Mike
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I had scopes that 2 of the magnification zoom wouldn't turn all the way (bought used from ebay since they were old Japanese Bushnells based on clarity and vintage a while ago) no noticeable press marks nor dents and one even wouldn't have much windage travel too. Sent to Bushnell they let me know the scope were damaged by too much stress on scope tubes but offered me Korean Banners instead since no direct Japan made replacements. I wasn't too happy not getting Japan made scopes but at least the Korean cheapies were brand new and and warranty was no question even after they claimed user error. If the damaged scopes were not shimmed then it would be even more concerning when you really think about it and they were Japan made scopes too. I witnessed a Chinese underlever Springer with almost a 1/4 inch of soda can shims that zoom would no longer rotate even after tryomg to loosen that scope ring and I did not want to see how bad the damage was but the guy didn't care anyway and just used his gun as-is.
A very good question to ask sellers of scopes #1 Are you the original owner and has the scope ever been shimmed? #2 has it ever been mounted on a spring gun?
You can't always physically see the irreversible scope damage however you can tell when it doesn't function 100% as it should like the zoom ring not smooth and consistent and limited elevation and or windage that won't allow zeroing properly nor can't optically center anymore.
You guys probably had noticed some time in your lives that using junk rings you had to loosen them to have the zoom and or windage and elevation to work properly and don't know nor care to what extent of damage was already done.
Knowledgeable folks optically center their scopes and lap their rings too unless it already passed the scope ring alignment measuring tool check which probably most people don't even know what they are anyway.
A very good question to ask sellers of scopes #1 Are you the original owner and has the scope ever been shimmed? #2 has it ever been mounted on a spring gun?
You can't always physically see the irreversible scope damage however you can tell when it doesn't function 100% as it should like the zoom ring not smooth and consistent and limited elevation and or windage that won't allow zeroing properly nor can't optically center anymore.
You guys probably had noticed some time in your lives that using junk rings you had to loosen them to have the zoom and or windage and elevation to work properly and don't know nor care to what extent of damage was already done.
Knowledgeable folks optically center their scopes and lap their rings too unless it already passed the scope ring alignment measuring tool check which probably most people don't even know what they are anyway.
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This is an interesting topic and I'm surprised I didn't see it before I posted a thread on this issue. I debating shimming on my FWB 124. I have both droop and windage issues. I've mechanically zeroed my scope (objective end placed on mirror method) and am shooting low and right. I've considered shimming but would only go .010" max ! Kind of also leaning on a droop compensating base mount 11mm to Weaver. Then adding some low Weaver style mounts with windage correction. Any thoughts? I've discussing this issue with Odoyle extensively.
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I shot a lot of small bore way back and never heard of adjustable mounts . I remember when bases with MOA built into them came on the seen. And have several now. I have been around shimming with a business card for years and never thought it a problem. I have seen this practice from well respected gun smiths way back. I have never been one for swapping scopes. So the scopes shimmed still are or were sold on the rifle. So maybe I never saw the problem I created.
However I would like to ask a question? I may not be thinking of all the angles. Well respected company make adjustable bases and rings for windage. A lot of people use them to center their scopes adjustment. isn't putting stress on a straight tube with an adjustable windage the same as the rings being out of parallel or plumb? Or is my thinking off?
However I would like to ask a question? I may not be thinking of all the angles. Well respected company make adjustable bases and rings for windage. A lot of people use them to center their scopes adjustment. isn't putting stress on a straight tube with an adjustable windage the same as the rings being out of parallel or plumb? Or is my thinking off?
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I would say your thinking is off and "angle" is the exact word that causes concern. It seems that adjustable rings allow the ring to be aligned as needed and then afterwards locked at the base. It doesn't seem like any "stress" is introduced. I know the Sportsmatch rings work this way-the rings are movable until locked and would "follow" the scope tube. In contrast, a shim in a rear ring introduces an angle in the scope tube that would be concentrated in the front ring with more contact at the lower front and top rear edges of the front ring (as well as at the top strap of the rear ring). The shim itself may not cause any damage if soft enough but the angle seems to be where the potential damage could arise. Many claim that they have shimmed without issue for a long time but as you ask is the damage noted then or later? Or is there no problem at all with shimming? Personally, I don't shim scopes.
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I am dense. Please look at this adjustable windage scope base from Leupold. Notice the front ring would stay stationary. The rear ring when adjusting left or right for windage would change the front and rear ring planes. Wouldn't it? Then read the note below that mentions "gross elevation" Please know I am not being argumentative just conversation.
https://www.leupold.com/scope-mounts/std-remington-700-long-range-rh-la-1-pc
https://www.leupold.com/scope-mounts/std-remington-700-long-range-rh-la-1-pc
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No problem, it's a good conversation. I'm not familiar with the Remington mount but I can tell you that Sportsmatch rings work as I described. Both front and rear rings pivot and tilt on their respective bases until locked so their is NO stress on the tube. Not certain of all other designs and I'm not 100% certain shimming would damage a scope. Seems to me it could so I don't do it. Might work fine and many claim it does.
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No issues with Remington 700 type bases since the front ring gives-rotates as you adjust the rear Windage. That's how you install the removable upper portion twist to detach rings anyway.
https://youtu.be/2GAWx0V2Z_c
https://youtu.be/2GAWx0V2Z_c
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Hard to twist the rings. "Exactly" I have dozens of double dovetail type rings of different makers. They will bend your scope if you turned them with the scope. The instructions warn not to use the scope to turn the rings in. However even if the ring turns on an an angle the set screws on the rear rings would hold that ring square. So the front ring and the rear ring would not be on the same plane. Ii think
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Hi All,
Since I discovered things like below for 11mm rails and pic rails, 30 or 20 moa normally does the trick for me. It also turns some of my short rings into taller rings.
For the $15 it gets the job done. I've even cut out the centers on some for magazine clearance. (If you cut out the middle the OAL of the adapter has to be maintained unless you want a "Z" in your scope tube!)
Enjoy,
Nugria
Since I discovered things like below for 11mm rails and pic rails, 30 or 20 moa normally does the trick for me. It also turns some of my short rings into taller rings.
For the $15 it gets the job done. I've even cut out the centers on some for magazine clearance. (If you cut out the middle the OAL of the adapter has to be maintained unless you want a "Z" in your scope tube!)Enjoy,
Nugria
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I just had to shim my scope because I was maxed out on height. I read that I needed to raise the rear scope end. I found the plastic packageing from a set of wrenches I got did the trick. Cut a piece to fit the rear saddle and it gave me lots of restored height. Zeroed the scope for my 30 yd range and all is good. Cut some strips of plastic for my shooting tool box
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Had a BSA 6-24x scope. Terrible thing, but it did work. Shimmed the rear by sandwiching one layer of aluminum from a soft drink can between two layers of black electrician's tape. One layer was enough to push the scope high.
As for damaging the scope, it pushes alignment out probably 1/3 mm to 1/2 mm at most. Virtually no risk of damage.
As for damaging the scope, it pushes alignment out probably 1/3 mm to 1/2 mm at most. Virtually no risk of damage.
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Well, yes, that's my opinion. I base that opinion on having done it with no damage,. The key is don't over tighten anything else. Those tubes are strong, just don't crank down on the screws as hard as possible you should be fine. Stick with manufacturers specs if you have a torque wrench. However, if someone is shimming, I doubt they have the proper tools. If they have proper tools, they've got more experience and would probably just buy the adjustable rings.
Shimming should be considered a stopgap after all.
Now, if you put 2 or 3 layers in, yes, you will probably damage the front portion of the scope when you tighten. If you need 2mm or 3mm of lift, you need adjustable rings.
Shimming isn't the best method to lift the rear of the scope, getting adjustable rings is far better, but will slight shimming automatically damage the scope? Absolutely not.
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Scopes can easily be damaged even without shimming if scope rings aren't lapped wjenever needed even when using expensive rings.
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Over the last 50 years I have seen many scopes with ring marks or damage. The odd thing is I have mounted hundreds of scopes. When young I used the cheapest I could buy and considered myself lucky to get that. I have shimmed a bunch of scopes also because that’s all I could do. Anyway I have never had one scope with ring marks. Is tightening everything even a key? Keeping all the ring gaps equal instead of cranking down on on side or one ring. I don’t know. I had some heavy recoiling contender pistols in rifle calibers and could not leave anything loose. No lessons hear, just wonder.
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I prefer to use plastic instead of soda can aluminum. It won’t scratch the scope. 2 liter soda bottles are about 0.010 thick and gallon milk bottles are around 0.015. I don’t recommend anything thicker.
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