June, 25

AR 15 Barrel Nut Shims: How They Improve Your Rifle’s Accuracy

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AR 15 barrel nut shims are an essential part of your rifle's assembly. When you're building or customizing your AR-15, it's important to ensure that all the parts fit together correctly. That's where barrel nut shims come in.

These small metal or plastic rings can help adjust the alignment of your upper receiver and barrel, ensuring a secure and tight fit. They come in different thicknesses and sizes to accommodate various configurations.

While some gun enthusiasts may overlook the importance of this tiny component, professional shooters and experienced gunsmiths understand its significance for optimal performance. In this article, we'll delve deeper into what AR 15 barrel nut shims are, why they matter when assembling a rifle, their types available on the market today as well as how to select them based on specific needs.

So if you're interested in learning more about these little yet mighty components that play an integral role in optimizing firearm functionality while also minimizing wear-and-tear over time then read on!

AR 15 Barrel Nut Shims: An In-Depth Guide

If you're a gun enthusiast, then you know how important it is to maintain your firearms regularly. One part that requires regular maintenance is the barrel nut. To keep your AR-15 in top condition, one must pay attention to the barrel nut shims.

What are AR 15 Barrel Nut Shims?

AR 15 barrel nut shims are thin metal plates that fit between the receiver and the barrel nut. They serve as spacers and help align the threads of both parts for an accurate assembly. These small devices may appear insignificant but can make all the difference when it comes to accuracy.

Why do You Need AR 15 Barrel Nut Shims?

When installing a new handguard or changing barrels, slight differences in thread pitch or position can cause misalignments between receiver threads and mating surfaces which could lead to degraded accuracy or worse – complete failure of firearm function under certain conditions.

AR-15s come in many different configurations with varying tolerances, so finding exact alignment through machining alone isn’t always possible without some additional assistance from shimming devices like these!

Using these tiny pieces of metal can significantly improve rifle accuracy by ensuring proper alignment during assembly. Moreover, they minimize wear on both parts by preventing them from rubbing against each other during operation.

Benefits of Using AR 15 Barrel Nut Shims

  1. Improved Accuracy – By using shimming devices like these during assembly ensures precise alignment between mating surfaces resulting in improved shot placement over time.
  2. Reduced Wear & Tear – It minimizes contact points and thus reduces frictional forces at critical areas keeping rifles functional for longer periods before requiring service.
  3. Cost Effective – Instead of spending money on expensive machinery work just use this affordable accessory for better results!
  4. Easy Installation – Installation process is fairly easy which means even beginners can do it themselves without much hassle!

How to Install AR 15 Barrel Nut Shims?

Installing a barrel nut shim requires precision and patience. Here are the steps to properly install one:

  1. Disassemble the upper receiver assembly from your rifle.
  2. Remove the existing barrel nut, being careful not to damage any of its threads or mating surfaces.
  3. Place one shim on top of another until you achieve an ideal thickness for proper alignment between receiver threads and mating surfaces on both parts (typically 0.001” – 0.003”).
  4. Carefully slide the shims over your barrel above where it meets with your upper receiver, ensuring they stay in place as you reattach everything back together.
  5. Tighten down screws evenly using torque wrench and appropriate torque values provided by manufacturer's instructions.

Comparison with Other Methods

There are other methods to keep AR-15s in good condition besides using barrel nut shims such as thread locker or timing nuts but these options have their drawbacks too:

Thread Locker: Using Thread locker can be messy, making it difficult for future disassembly of components that were locked into place previously.

Timing Nuts: Timing nuts require extra effort during installation since they must be lined up perfectly before final tightening occurs; this task may prove challenging even for experienced gun owners due to different manufacturing tolerances among manufacturers producing parts used within an AR-15 platform.


Making use of AR-15 Barrel Nut Shims is a cost-effective way for improving accuracy while also reducing wear & tear on critical components within rifles! Installs are easy enough that anyone can do them without difficulty ensuring perfect results every time when done correctly!

So if you want accurate shots from your favorite firearm consider purchasing some quality shimming devices today!


What are AR 15 barrel nut shims and why are they important?

AR 15 barrel nut shims are small, thin metal washers that fit between the receiver and the barrel nut of an AR-15 rifle. The role of these shims is to help align the gas tube with the gas port in order to ensure proper cycling of rounds in semi-automatic mode. Proper alignment between these two components is critical for reliable function, accuracy, and longevity of your firearm.

The purpose behind shim usage is that it can correct small variances or discrepancies present within certain AR-15 upper receivers or barrels that may cause misalignment issues without having to resort to more extensive modifications such as re-threading holes or machining surfaces.

In other words, having properly aligned gas ports means fewer malfunctions while shooting and a longer lifespan for your weapon.

Are there different sizes available when it comes to AR 15 Barrel Nut Shims?

Yes! There are several different sizes available when looking at this small but nifty accessory. These size differences often relate specifically back to differing manufacturers' specifications regarding their respective uppers or lowers.

For example, some brands will produce thicker receivers than others which can call for thicker shimming; conversely thinner manufactured receivers could require thinner sized shim counts. It's best therefore before you start buying them online simply based on price alone – research your own specific parts/brands beforehand so you don’t end up purchasing the wrong ones!

As a general rule though most packs will offer variety across thicknesses from ~0.001" all the way up through about ~0.005".

How do I install these Barrel Nut Shims correctly?

Installing an ar-15 barrel nut shim isn't too difficult if you’re familiar with basic tools/handling weapon systems but there’s definitely room for error if not done right! Here's a quick step-by-step guide:

  1. First make sure your weapon is unloaded and the pieces are separated.
  2. Next, place the barrel into your upper receiver.
  3. Then slide the barrel nut over it and tighten it by hand until fully seated.
  4. Take a torque wrench at this point (ideally with a setting of around 35-80 ft-lbs depending on manufacturer specs).
  5. Tighten further using appropriate torque settings to reach specification requirements – do not exceed these as damage can occur!
  6. Now, insert shims between the receiver face and nut until you get proper alignment.

One important aspect to note here is that there's no "one size fits all" approach when selecting which shim thicknesses or quantities to use; careful testing/observation must be conducted before settling on an optimal combination.

Do I need professional help installing my Barrel Nut Shims?

While anyone who has some basic technical knowledge can perform this task successfully…there’s definitely still potential for errors! If you’re unsure about how to install them yourself or don't feel confident in doing so then seeking out professional installation by someone experienced could be worthwhile.

If done incorrectly, it could lead to malfunctions like gas blockages during shooting sessions – something that should never happen! At worst case scenarios dissassembly may again be required if this happens!

It's always better safe than sorry especially when trying new things so if you're ever questioning whether or not you have enough expertise just leave installation up for experts within their fields!

Can I re-use AR 15 Barrel Nut Shims?

The answer here isn't really definitive since there are various factors involved: frequency of usage in rifles being one factor along with wear & tear induced from cleaning/maintenance practices as well.

In general though shim sets are relatively cheap compared other rifle accessories so replacing them every now and then wouldn't hurt especially if they start showing signs of wear / corrosion / rusting which means they likely won't work as well under pressure/stress.

As always, always perform regular checks on your firearm to make sure all parts are working correctly and efficiently.

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