Shimming scope rail

[JimD]

I have used plastic shims that go into the scope rings sold by Hawke to get my scopes closer to optical center and they work but are a little pricey. I think I found a better way and it's free. My P35s have a one piece scope rail that is attached with three screws to the yokes that clamp the airtube and barrel together. I had a can of regular coke in the fridge I was never going to drink (not a fan of the sugar included) so I drained it and cut it up. The P35 scope rail is a little U shaped so I made the shims the width of the inner part where the screw holes are. I discovered by experimentation that 8 layers of the coke can got me a little past optical center of my scope. The resulting thickness is almost exactly 1mm. So I have more clicks Up than Down now although only about a Mil (10 clicks on it's scope). So I am closer to optical center than without shims and I have lots of room to go up for a longer range zero. 5 layers would probably have put me at about optical center.

If your gun(s) have a one piece scope rail you may want to try this. I am sure a lot of you already do.

I'm editing this mainly to add 3 pictures but also to say that I did this on another gun, a Stoeger bullshark, and 8 layers of shim were too much. I used 5 and the scope still has over 100 up clicks available and over 70 down clicks. That's about where I wanted it. It's nice you can easily clip off a few layers.

Picture 1 has the under side of the P35/Stoeger bullshark scope rail with a folded up shim setting beside it. Picture 2 has that shim pack in the rail and Picture 3 shows the back of the rail on the gun with the shim pack peeking out.

 

[GeneT]

Get a plastic shim assortment ("Precision Brand" - check Amazon). Use them to get yourself oriented and then bed the whole mess with epoxy bedding. For a much better description, check out "The Book of Rifle Accuracy" by Tony Boyer. It's aimed at (benchrest) powder-burners, but much of it is applicable to air rifles as well.

GsT

 

[XSUltimate]

I use my old 35mm negatives from pictures. work awesome in the rings!
Thx
Dan

 

[Ta-Ta Toothie]

I use my old 35mm negatives from pictures. work awesome in the rings!
Thx
Dan

I wonder how many people these days know what those are...

 

[JimD]

I wasn't too worried about the Hawke product damaging a scope and I think any sort of plastic is unlikely to damage the scope tube but I prefer to shim the rail. Doing that does not stress the scope at all.

 

[MongooseV8]

I never use shims. Knowing how complicated and fragile most scopes are, I dont like the idea of making the tube flex more than it already has to. The closest I would use is something like the FX No Limit or Eagle Vision rings if you need the elevation. Or Warne makes a series of rings with offset rotatable plastic inserts. If you are using a decent scope what is the advantage of getting the erector/lenses mechanically centered?

 

[JimD]

I wanted to be closer to centered because I want more elevation adjustment available for when I shoot at 100 yards or more. I was using up a lot of the available "up" elevation to get sighted in at 30 yards. The shims do not stress the scope at all, they are under the rail the one piece scope mount is attached to. With the shims I am a bit below being optically centered so I have over half the adjustment range available to go up for a longer range zero.

 

[namo81]

Instead of shimming scopes, I have started using the Monstrum adjustable rings. They make a set that allows you to freely adjust the scopes angle so both the front and rear ring align with each other correctly. This makes it so there are no uneven pressure points on the scope's tube.

I used a pair on my Hatsan 135 Vortex to raise the front of the scope up a bit since I was running out of elevation adjustment in my Athlon Argos HMR. Since this rifle is a notorious scope destroyer, I didn't want to use shims which could make things even worse. They've worked flawlessly so far, allowed me to bring the scope as close to optical center as possible, and after a year of use the Athlon is still in good health.

Not sure what the general opinion of Monstrum's rings and mounts are around here, but I use them on several of my air rifles and have been really happy with them.

 

[JimD]

I am just posting this reply to let everybody know I added some pictures - in case that helps somebody. I added them in the original post by editing it so it didn't show up as a new response.

 

[bchannell]

Whatever works, I've used both. As long as the shims are one or two you're fine. The key is when tightening scopes, shims or not, don't go too tight. If it's not a heavy springer, then scopes need very little torque to hold them. Scopes are relatively tough, I've only seen damage when horrendously over tightening the rings and even then, when the rings were untightened the scope worked normally, even though there were heavy permanent marks.

 

[JEFFPPC]

Burris Signature Zee Rings with inserts.

 

[Duckfish]

I have used plastic shims that go into the scope rings sold by Hawke to get my scopes closer to optical center and they work but are a little pricey. I think I found a better way and it's free. My P35s have a one piece scope rail that is attached with three screws to the yokes that clamp the airtube and barrel together. I had a can of regular coke in the fridge I was never going to drink (not a fan of the sugar included) so I drained it and cut it up. The P35 scope rail is a little U shaped so I made the shims the width of the inner part where the screw holes are. I discovered by experimentation that 8 layers of the coke can got me a little past optical center of my scope. The resulting thickness is almost exactly 1mm. So I have more clicks Up than Down now although only about a Mil (10 clicks on it's scope). So I am closer to optical center than without shims and I have lots of room to go up for a longer range zero. 5 layers would probably have put me at about optical center.

If your gun(s) have a one piece scope rail you may want to try this. I am sure a lot of you already do.

I'm editing this mainly to add 3 pictures but also to say that I did this on another gun, a Stoeger bullshark, and 8 layers of shim were too much. I used 5 and the scope still has over 100 up clicks available and over 70 down clicks. That's about where I wanted it. It's nice you can easily clip off a few layers.

Picture 1 has the under side of the P35/Stoeger bullshark scope rail with a folded up shim setting beside it. Picture 2 has that shim pack in the rail and Picture 3 shows the back of the rail on the gun with the shim pack peeking out.

View attachment 450346

View attachment 450347

View attachment 450348

There are fx no limit rings for sale in the classifieds right now

 

[JimD]

I have used Hawke shims and I know about Burris rings and FX no limits. But respectfully they are not like shimming a one piece scope rail. Shimming the rail is like buying a gun with a 20 MOA rail. It works with any rings. The cost is zero dollars. Just cut up an empty soda can. No stress on the scope. No complicated installation. The worst thing that can happen is you find you did not use enough or used to many layers of soda can. The solution in either case requires removing the scope and rail and trying again. A few minutes time. It requires a one piece rail in my opinion but if you have that, to me it's a no brainer. Without the shims, I did not have elevation adjustment enough to get to 100 yards. With the shim I can go significantly beyond 100 yards.