Thread: Scope running out of elevation adjustment (Shooting too high)

Originally Posted by Synthetic

Hi team,

I have a Weaver Grand Slam 3-12x42 with side focus.

At first I could not hit an A4 paper at 25m, then I realised it was shooting way too high.
After dialling the scope to the end of its elevation adjustment limit, I was still shooting about 25cm high at 25m.

Tried setting it up on a CZ452 22LR as well as a T3X in 223, with different rings, both with the same result.

Did a search on the forum and saw a few similar previous posts, which suggested swapping the front and rear rings around. I tried but it did not help.

The only trick I can think of now is to shim the rear rings of the scope using a piece of coke can to drop down the point of impact. However some posts suggested doing so may damage the scope.

So my questions are:

- Will shimming using a coke can piece be too risky?

- Should the shim be inserted between the scope tube and the ring? Or between the ring and the base?

- Does wrapping the shim in some clothes to provide a softer contact area sound like a good idea?

- Any other suggestions?

Thank you very much!

Greetings Synthetic,
First a coke can is just not going to cut it. Based on a 125 mm ring spacing you will need a 1.25 mm shim to get the shots in the middle with adjustments bottomed out and likely 1.5 to 2.0 mm in practice. First however you might want to check that the adjustments are working properly. Using a large target with the aiming point at the bottom and at 25 metres wind the scope up and down and left to right firing a shot at each setting to see if the scope is doing what you tell it to. You might want to run the adjustments through their range first to distribute any lubricant in the mechanism. I gather this helps with scopes that have been idle for some time. After checking this and the other items above if you still want to shim it the shim should go between the scope base and the receiver ring at the front ring. You should never shim inside the rings. You will likely need longer ring screws.
It might be easier to just replace the scope.
Regards Grandpamac.