Choosing the right buffer tube for your AR-15 or similar firearm is crucial for proper functionality and safety. Getting the wrong one can lead to malfunctions, poor performance, and even injury. This guide will walk you through identifying the buffer tube you need, whether you're building a rifle from scratch or replacing a worn-out component.
Understanding AR-15 Buffer Tubes
Before we dive into identification, let's clarify what a buffer tube is and why it matters. The buffer tube is a hollow cylindrical component that houses the buffer spring and buffer weight. These components work together to manage the recoil of your firearm, ensuring smooth cycling and reliable operation. Different buffer tubes exist to accommodate different stock types and overall rifle configurations.
There are primarily two main categories to consider:
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Commercial Buffer Tubes: These are the most common type and are designed for standard AR-15 rifles. They typically have a diameter of 1.125 inches.
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Mil-Spec Buffer Tubes: These tubes are manufactured to tighter military specifications and may have slightly different dimensions, although they are largely compatible with commercial parts.
The critical dimensions to identify are the diameter and length of the buffer tube.
Methods to Identify Your Buffer Tube
Here are several ways to determine what buffer tube you currently have or need:
1. Visual Inspection and Measurement:
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Inspect the Tube: Carefully examine the buffer tube itself. Look for any markings or stamped information indicating the manufacturer and/or specifications. This is the easiest way if the markings are clear.
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Measure the Diameter: Use calipers or a precise ruler to measure the outer diameter of the tube. This will quickly tell you if it's commercial or potentially mil-spec.
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Measure the Length: Measure the overall length of the tube, excluding any parts that attach to the receiver or stock. Note this length – it's crucial for compatibility with stocks.
2. Checking Your Existing Setup:
If you already have an assembled rifle, you can check several areas to gather information:
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Check the Stock: Many stocks are specifically designed for either commercial or mil-spec buffer tubes. The stock itself might have markings indicating compatibility. The manufacturer's website or documentation might provide details about the compatible buffer tubes.
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Examine the Receiver Extension: The receiver extension is the part of the lower receiver that the buffer tube screws into. Some manufacturers might stamp their buffer tube type on this part.
3. Referring to Manufacturer Documentation:
If you know the manufacturer and model number of your rifle or individual components, you can often find this information in the manufacturer's documentation or on their website. This is particularly useful if your rifle is custom-built.
Determining the Buffer Tube You Need for a New Build:
When building a new AR-15, selecting the right buffer tube is crucial. Here's a process to follow:
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Choose your Stock: Decide on the stock you want to use. This will often dictate the length of the buffer tube you need. Check the stock's specifications to verify compatible buffer tube lengths.
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Commercial vs. Mil-Spec: Unless you have a specific reason to use mil-spec (e.g., for a specific build), commercial buffer tubes are generally sufficient and widely available.
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Buffer Tube Length: Buffer tube length is determined by the desired overall length of the rifle and the chosen stock. Longer tubes are required for longer stocks, while shorter tubes are used for carbine-length stocks.
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Verify Compatibility: Always ensure the buffer tube you select is compatible with your lower receiver extension.
Conclusion
Finding the right buffer tube can seem daunting, but by using these methods and carefully checking specifications, you can ensure a proper fit and reliable performance. Remember to prioritize safety and always double-check your measurements and compatibility before installation. If you remain uncertain, consult with a qualified gunsmith.
