Shooting Mystery is reader-supported. When you buy through links on our site, we may earn an affiliate commission. Learn more

Rifle Scope Shimming: How to Do It Right in 5 Easy Steps

Scope Shimming

When it comes to target shooting or hunting, gun precision is KEY.

You want your scope to be as accurate as possible — no matter what gun you use!

But sometimes, things happen for various reasons, and your scope gets misaligned and experiences barrel droop.

I’ve wasted bullets because of this, and I felt very annoyed and hopeless.

So, how do you fix it? SHIMMING YOUR SCOPE.

What is Scope Shimming?

Shimming isn’t a new concept, and this has been one of the best go-to remedies for many.

Shimming is probably one of the greatest things you can do when you’re experiencing barrel droop and need a quick fix.

All I had to do was move my scope within the mount, and I was done!

And as a result, I’ve got one rifle in your arsenal line that can make the best shot.

It helps them improve their shot and range, especially when the competition is tight.

Rifle Scope Shimming for More Windage & Elevation: 5-Step Guide

I used to think shimming was complicated, so I never bothered to try it.

With all the different rifle types and parts out there, you’ll probably feel more comfortable leaving the matter to an expert who can do it properly.

But with the proper guidance, you can do the shimming yourself!

You can align the scope on your gun correctly and get ready for the competition!

Don’t worry; shimming doesn’t take rocket science. As long as you follow the steps, you can adjust and fix your scopes in no time.

Step 1: Choose the Material of Your Shim Stock

Step 1: Choose the Material of Your Shim Stock

The beauty of shimming is that you can choose almost any type of material for your shim.

In general, there are two things you need to keep in mind:


First, the material must be flexible enough.

I was surprised to know I can use many common everyday materials: Aluminum cans, brass, clothes, plastic bottles, or plastic containers.

Be mindful of how thick or thin the materials are.

In general, aluminum is one of the materials preferred by many, myself included, since it’s not too thin or thick.


And second, the material thickness you choose should be able to fit the scope rings.

In my experience, this part took some trial and error, but with a little patience, you’ll find the right thickness soon enough.

Do you always have to DIY scope shims? Not necessarily. Today, you can already buy scope shims that fit the size and cut of your scope rings.

Step 2: Measure the Correct Size for Your Scope Rings

Step 2: Measure the Correct Size for Your Scope Rings

In my experience, finding the right shim size was quite tricky, especially since I was using a new scope.

The shims may be as thick as you want, but…

Does it fit nicely on your scope tube or the back or front ring? How many inches of shims do you need?

A big mistake I made was when my shims extended PAST the scope rings attached. That’s a big no-no! 

You should cut the few extra inches off if that happens to you.

As much as possible, the shim should never extend beyond the edges of your scope ring.

But if you encounter this problem, don’t worry; there’s still a remedy.

You can use sandpaper to make enough adjustments to the shims, and you’re all set.

Step 3: Remove the Rifle Scope and Place Your Shims

Step 3: Remove the Rifle Scope and Place Your Shims

I can’t emphasize enough how IMPORTANT it is to properly do this step!

You’ll be removing your rifle scope, and you want to make sure you set aside all the parts and screws.

Here’s how to do it:

Using a wrench, gently remove the rifle scope and detach the scope ring. Be sure to leave the bottom rings attached to the rifle.

Start placing your shims on the rear scope ring. Make sure to add the rear scope ring one at a time.

You can always add an extra rear ring later than have a hard time detaching the shims.

In general, I don’t recommend placing more than two shims.

But if you end up using two or more shims, you can use adhesive to hold them together.

Step 4: Bolt the Rifle Scope Back and Level

Step 4: Bolt the Rifle Scope Back and Level

Once you’re happy with your shims, it’s time to place your rifle scope back. 

But before you put the screws back on, sight your scope and check if it is LEVELED.

It will be hard to adjust the scope shims if you’ve already tightened the scope back to its reticle.

Save yourself from this dilemma, and level your scope correctly. Once you’re satisfied with the alignment, tighten your air rifle scope back in place.

Step 5: Check the Alignment and Make the Necessary Adjustment

Step 5: Check the Alignment and Make the Necessary Adjustment

Finally, once you’ve installed the shims and made enough adjustments, it’s time to check the alignment on the barrel.

Check the scope to see if the changes are done correctly. You can continue making the necessary adjustments until you’re satisfied.

PRO TIP: Make sure you can zero in on your target and hit your mark during test fire. If you think there’s still something off, you can fix your scope ring accordingly.

Why Should You Shim Scope Rings?

There are a lot of benefits when you shim a scope, besides adjusting the front and rear mount or elevation.

There could be an instance where you’re in the middle of a competition, and you need to get your aim in line.

Should you shim your air rifle? Here are some reasons to convince you:

1. It Saves You Time

1. It Saves You Time

First, it is a big TIME-SAVER. It doesn’t take a lot of time, and it’s the best solution for anyone who wants a quick fix.

Unlike changing the adjustable mounts of your rifle scope, which takes quite some time and skill.

2. Make Adjustments as You Please

2. Make Adjustments as You Please

Second, you can always fix the alignment based on your desired accuracy. 

This is a huge convenience for me as I don’t have to spend on adjustable mounts, some of which might not even be suited for my rifle.

Basically, I don’t have to spend a fortune to improve my range.

3. Save on Costs

3. Save on Costs

Third, choose a shim over adjustable mounts if you want to save extra bucks.

I realized that replacing or changing my scope mounts is a lot more expensive in the long run when compared to adjusting the shim.

Is It OK to Shim a Scope?

Generally, it’s pretty safe and normal to shim a scope, especially if you’re particular about doing it correctly.

However, you have to be careful when you shim your scope.

As much as possible, only use the BEST material and quality you could possibly get, like aluminum.

Be mindful of how thick or thin it is and how the shim fits your scope rings!

Choosing a shim that’s not fit for your gun might cause some misalignment damage in the long run. 

Remember, choose a shim that’s not too thin or thick.

Also, be careful how you tighten the shims to avoid damaging your scope.

Frequently Asked Questions

Frequently Asked Questions

Can You Shim a Picatinny Rail?

Shimming a Picatinny rail mounting system has gotten pretty common these days. Many people are less familiar with the job, and some even offer their services!

The same goes when you need your other guns fixed, including air guns!

Just make sure to tighten the screws back when you’re done, and you’re all set.

Can You Shim a Red Dot Sight?

Yes, you can shim a red dot just like any other scope.

However, you must be careful and mindful of your shim.

You can buy manufactured shims if you don’t want to DIY the shims for your red dot sights. This will cut down the steps you have to take and save your time.

Moreover, if you’re unsure how to shim your red dots properly, some people provide their services and do an expert job.

Final Words

The next time you need to adjust your scope, consider shimming!

Although my usual go-to is to change the mount around your scope tube, it doesn’t always have to be the case.

Shimming might be the best solution you need to raise or lower your scope. And the results? Your target is on point, and no more annoying barrel droop.

This quick-fix remedy is a great life skill you can have in your back pocket that’s sure to come in handy in the future.

Load your ammunition and shoot the bullet!

About the author