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How to Fix a Collapsible Stock AR-15 To The Buffer Tube

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From wanting a more stable stock to needing a fixed stock depending on where you live, there are several reasons you might want to fix your collapsible stock. While there are plenty of options for fixed stocks on the market, they may not be your favorite. So how can you fix your favorite collapsible AR-15 stock?

We will go over some common methods, including a step-by-step guide, to fix your collapsible AR-15 stock.

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How to Fix an AR-15 Collapsible Stock to the Buffer Tube

One can permanently fix a collapsible stock in a couple of different ways. These methods include pinning the stock to the buffer tube with a standard roll pin or buying a device that restricts the movement of the stock, which is often much more effortless.

Products like the Strike Industries AR Stock Stop are a great way to keep your stock from moving. Devices like this serve one purpose: to remove the adjustable feature from your favorite rifle stock.

The Stock Stop achieves this by blocking all but one locking stop on the receiver extension, leaving you with only one position for your stock rendering it no longer adjustable. There are only a couple of steps to install this device, remove the stock, cut the device to size, and drop it in the receiver extension.

How do you take off an AR-15 stock? It’s simple, look for a small release, commonly found on the bottom of the stock, and pull it downwards away from the buffer tube. With this pin pulled down simply slide the stock off the buffer tube. Repeat this process in reverse to put the stock back on.

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However, you may want a more robust solution to fixing your stock. Doing so will require a little more work, such as pinning the buffer tube and stock with a roll pin or screwing the stock to the tube to ensure it cannot be adjusted.

How is this done? It is recommended to take your rifle to a reputable gunsmith so they can complete this process. It is also worth noting that modifications that require drilling into your rifle or buffer tube may very well void your manufacturer’s warranty. Here is what your gunsmith will do to fix your AR-15 collapsible stock to the buffer tube.

Pinning The Stock and Buffer Tube

Before handing off your AR-15 rifle to your gunsmith of choice be sure you extend the stock to your desired length. It is crucial to have your desired length of pull, not only for comfort but if you are using a magnified optic length of pull is vital for eye relief.

The optimal place to drill the hole is at the front of the stock, where it meets with the buffer tube. Avoiding the cylindrical portion of the buffer tube that holds the buffer and buffer spring it will be drilled into the square part at the bottom that has the adjustment holes.

ar15 magpul stock

Be sure the gunsmith drills through both sides so that you can remove this pin in the future if needed. Once the hole has been drilled, the roll pin will be tapped into place using a roll pin punch. The roll pin should pass through both sides of the stock and buffer tube ensuring you have a sturdy fixed stock.

Changing to a Fixed Stock System

Another common option is to completely change the buffer tube and stock to a fixed stock style. This includes removing the existing adjustable stock and buffer tube, if needed, and reinstalling a non-adjustable stock. The process is simple, but you will need some simple tools to get the job done.

Tools Needed

This method will require a couple of gunsmithing tools. If you are an avid AR-15 builder or regularly do maintenance on your rifle, you may have some of these lying around.

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You will need an AR-15 armorer’s wrench to remove the castle nut, if you need to remove the buffer tube, and the appropriately sized hex or Torx wrenches for your specific stock.

Please note that most fixed stocks you can buy will not require you to remove the buffer tube. For example, the Magpul MOE fixed carbine stock will simply slip on the existing buffer tube and secure with a locking screw, making for an easy installation.

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Let’s go over the steps to install a common fixed carbine-length rifle stock. First, just like earlier, you will need to remove the adjustable stock by locating the pin or screw found on the underside of the stock and pulling it downward. With this pulled down, you can now slide the stock off.

Now with the stock removed, you can simply slide the new fixed stock onto the buffer tube. Most carbine-length fixed stocks will be secured at the front of the stock near the end plate of the receiver. Once this is located you can install the screw provided with your fixed stock. With this screw installed, you are done it’s that easy!


Now you know some common ways to turn your collapsible stock into a fixed one. Not only will these methods allow you to use your favorite stock still, but you will gain the rigidity of a traditional fixed stock.