Shim a Scope?

[baddarryl]

Hi all. I have a Nitrex TR1 (Weaver Grand Slam) on a 10/22 Target. The best I can get out of it is about 20 MOA to the right. Assuming an 80 MOA range of adjustment I am wanting to move poi about 60 MOA left in order to get to the center adjustment range. I guess I can shim the rear or the scope left with soda can strips or something. Does anyone have an idea how I can calculate that much MOA shift with shims and the material to use? I have had this rifle zeroed with another scope so I don't think it is the rifle.

Maybe my setup? I only eyeballed level when installing it. Thank you.

[std7mag]

Sounds like you need to start from scratch.

Most people talk moa of a scope relative to elevation. Not windage.
Something is out of alignment somewhere.

[Triphammer]

Was the other scope in these rings or a different set of rings?

[baddarryl]

Same rings.

[taylorce1]

Something is definitely wrong. However, I think your math is wrong as well! Does the scope have 160 MOA of adjustment in Wingate? I think you only need to move it a total of 20 MOA if you want to center you windage adjustment, if your scope only has 80 MOA of total adj7stment.

Soda can shims really don't work on left to right adjustment, they work okay on elevation adjustment. Easiest way to adjust Wingate on that scope is with a set of Burris Signature rings with MOA offset inserts.

[Mobuck]

Suggest you look at the Burris eccentric ring inserts. Shimming on the horizontal doesn't work and will damage scope tube.

[baddarryl]

Something is definitely wrong. However, I think your math is wrong as well! Does the scope have 160 MOA of adjustment in Wingate? I think you only need to move it a total of 20 MOA if you want to center you windage adjustment, if your scope only has 80 MOA of total adj7stment.

Well just something I did quickly in my head. To clarify, with the scope cranked all the way to the left the POI is still 20 MOA to the right. I am assuming 80 MOA adjustment via Weavers specifications. I just made a graph and yes, 60 MOA would get me fairly close to the center of adjustment range.

I think I am going to get some Weaver adjustable rings. It depends on what I can get fastest. I have to loan this rifle to someone Saturday for an Appleseed. Hopefully the LGS's will have a solution.

[taylorce1]

First off you need to check your actual range of MOA adjustment on your scope. I didn't think Nitrex offered the 2-8 power scope with 80 MOA of adjustment only a 3-9X40 would close, so I'm not sure you have the same MOA range. So max the adjustment to the left or right and then turn it the other direction counting clicks and divide by two. That'll let you know exactly how many clicks you have in windage.

How much internal windage adjustment did your old scope have? If you were close to center of adjustment shooting the same ammunition, I'd say you screwed something up mounting the Nitrex scope, your rings/base is out of alignment compared to the bore, or your scope is the problem. However without checking the actual click value left to right on your scope we have no clue if your scope actually has 40 MOA of adjustment left or right of center on the scope.

You might try putting the old scope back on and seeing how it shoots, if it is a good scope.

[Unconventional]

I know it sounds ridiculous, but make sure that you've been turning the windage knob in the correct direction... I'm not trying to be a smart ass here. You may have already considered this. I've made this mistake myself in the past, and I've seen other guys do it as well, though not as much as may have happened here.

I hope you get it sorted out!

[cptjack]

some one piece mounts have 2 screws on rear of mount to adjust windage

[baddarryl]

First off you need to check your actual range of MOA adjustment on your scope. I didn't think Nitrex offered the 2-8 power scope with 80 MOA of adjustment only a 3-9X40 would close, so I'm not sure you have the same MOA range. So max the adjustment to the left or right and then turn it the other direction counting clicks and divide by two. That'll let you know exactly how many clicks you have in windage.

This is the TR1 3x9x42. I looked on Weaver's site and most of their Grand Slams had 80, a few had 60. I will do that to be sure.

[QUOTE]How much internal windage adjustment did your old scope have? If you were close to center of adjustment shooting the same ammunition, I'd say you screwed something up mounting the Nitrex scope, your rings/base is out of alignment compared to the bore, or your scope is the problem. However without checking the actual click value left to right on your scope we have no clue if your scope actually has 40 MOA of adjustment left or right of center on the scope. [\QUOTE]

I have no idea as I bought the rifle without the scope and then went back and bought the scope and rings that were previously on it. Plopped it on and it zeroed. Took it out and put the Nitrex in the same rings. It is an older Japanese Tasco fixed 24x. Too much for my purposes.

You might try putting the old scope back on and seeing how it shoots, if it is a good scope.

See above. I think I am going to take the whole thing off remount and see what happens. In the interim I am going to order some Weaver adjustable rings as I have to have this thing zeroed Saturday. I have a Simmons Mag22 on an older Marlin, but I really don't want to mess with that as it is dialed in.

[baddarryl]

So I took it all apart last night and started leveling and tightening everything up. The the rear screw holding the Weaver base to the top wasn't really loose, but took about three quarters of a turn to get nice and snug. Took it back to the range today and was able to get it sighted in just fine. Thanks everyone.