# Shimming Scope Base



## RBoomK (Feb 10, 2011)

Guys, I need some technical advice. I recently mounted a new scope on my Savage 110. All components had good, solid fit and were properly torqued. Headed out for sight-in last weekend and soon became extremely disgusted. First shot was about 20" high and 2" left of center @ 100 yards. Windage came in fine after adjustment, but bottomed out elevation dial and gun is still shooting 8" too high. The scope is a Weaver GS 6-20x40 and only has approx 25" of elevation adjustment. I hate the thought of having to shim base, but at this point it is my only option. I reset elevation dial to center - to determine POI, and I'm right around 13" high.

Any ideas as to what thickness of shim stock I will need to get me close without having to remove the base several times?


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## Mojo1 (Sep 8, 2007)

I couldn't open you picture for some reason the link was messed up. What kind (brand and style) of bases are you using?


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## RBoomK (Feb 10, 2011)

I just fixed the pic, Mojo. Thanks.


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## Al Hansen (Sep 7, 2007)

Cut up a soda pop can to the proper size you need. I'd start w/ two pieces and go from there. Or you can buy shims from a gun shop and pay several $$'s and get the same thing. Let us know how it goes. Inguiring minds want to know.


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## RBoomK (Feb 10, 2011)

Base is a Weaver 1 piece - #413, and rings are the six hole 1" in medium height.


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## roper (Sep 27, 2010)

Hey RBoomK,

A few months ago I had this same problem, but mine was on a Ruger 10/22. Like you I asked for some help here. I was told to google "shimming a scope" and found a pretty helpful youtube video. Long story short, use a pop can to make your own shims. Cut it (don't use your wifes good scissors!) so that it fits under the base and you can't see it. Instead of drilling the holes for the screws to go through, I used a paper punch, much easier and your not as apt to cut yourself if it catches on the drill bit, and a much cleaner hole in the end. I started out with two shims, and had to add two more for a total of four shims. It was hard for me to think that a couple of skinny little shims could make that much difference, but it does. Good luck and hope this helped.

http://www.youtube.com/results?search_query=shimming+a+scope&aq=f


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## RBoomK (Feb 10, 2011)

Thanks for the link, roper. I appreciate it.

Thanks, Al.


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## Al Hansen (Sep 7, 2007)

Good job roper. Ya beat me to it. 8)


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## chet (Sep 7, 2007)

I'm un-familiar with savage's, but in the pic it looks like the rear of the base is thicker than the front. If that is the case, can you flip it around? essentially raising the front/lowering the rear of the scope? Bolt hole spacing may prevent this. just a thought


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## goonsquad (Sep 15, 2010)

Is that rail a 10, 15, or 20moa base? Seeing how you're 20" high, it almost seems like its your rail base.


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## RBoomK (Feb 10, 2011)

gs,
The pic is somewhat of an optical illusion. It is just a standard (0 moa) base. The base actually is "thicker" in the rear due to being a pre-2003 receiver. The rear on these receivers are flat and the front is round.


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## BPturkeys (Sep 13, 2007)

Get some new rings and bases...I recommend Redfield.


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## longbow (Mar 31, 2009)

I'm an industrial mechanic by trade so I couldn't help but grab this one by the scruff of the neck and shake out the details. First I measured my bases center-to-center on my latest gun . I came up with 4.75". Using those two points as anchor/fulcrom points I came up with .0014". So for every .0014" rise in the back you will get 1 MOA rise at 100 yards. Since you were talking about using popcan shims, I went to the garage and drank a sacrificial Keystone just so i could measure the can thickness. I got .004" thickness.
One popcan shim should give you 2.8 inch rise at 100 yards using 1.047 as a MOA, not 1 inch.
Since your shooting high, shim the front base.
I seriously wonder why you're shooting that high with factory bases, scope and rifle.


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## Al Hansen (Sep 7, 2007)

Way to go Longbow. Sacraficing yourself like that. 8) :lol:


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## RBoomK (Feb 10, 2011)

longbow, you rock! I am also seriously wondering why this rifle is so far out. I purchased it through a friend of a friend deal, and the excellent condition of the rifle leads me to believe it has had very little use - as he had stated. I had been entertaining ideas that it had received an extremely hard hit on the bottom of the muzzle end of barrel, thus tweaking it upward, but no such evidence. Although it is shooting high, the groups are nice and tight (the best being right around .6") Maybe it just wants to be zeroed at 500 Yards! LOL


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## longbow (Mar 31, 2009)

Here's two things that come to mind. I had a scope that shot high like yours. It slid off the side of the truck and bend the scope tube. I had to toss the scope. Could your scope be bent or otherwise damaged? The other, is a set of bases that were made wrong, however, that's a long shot.
Your gun is one of the finest guns, (accuracy-wise) there is. I doubt your barrel is bent or I don't think it would shoot tight groups like it does.
I hope you get to the bottom of this and let us know. I'm running out of Keystones.


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## RBoomK (Feb 10, 2011)

Scope was purchased brand new and arrived well packaged. It hasn't suffered any abuse. I've mic'd the height of both rings - both exactly the same. I'm going to go see if I can somehow get an accurate dimension on drop from front to rear of receiver and then verify it with the base. I hadn't really thought of that until one of you guys mentioned it. The base might just be a POS. Thanks for your help.

p.s. Save me a beer(s), I might need it before the nights out!


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## RBoomK (Feb 10, 2011)

Thanks to goonsquad for getting my wheels turning with his mention of a canted base, I figured out a way to mic the sucker and lo and behold..... +.028" high in the rear.

I don't want longbow's head to swell with his precise calculation, but if you punch in the numbers .028" divided by .0014" you get 20 - Which was how many inches + this gun was shooting. I ordered a new base.

Thanks for all of your help with this.


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## longbow (Mar 31, 2009)

RBoomK said:


> I don't want longbow's head to swell with his precise calculation,


Too late. :mrgreen:

Good to hear you got it figured out!


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## BPturkeys (Sep 13, 2007)

BPturkeys said:


> Get some new rings and bases...I recommend Redfield.


just sayin

but really, as long as the crosshairs are movin when you turn the knob and the groups are tight...got to be the rings or base and almost always the base. I just like the bases that give you a little left to right adjustment like the Redfields or Leopolds, probably some other good ones out there also.


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## RBoomK (Feb 10, 2011)

Thanks for all of your help, guys. The Weaver base went into the trash and the rings went back into the misc. parts bin. I went with an EGW base and EGW Practical rings. Test drive and range report coming soon.


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