The Commercial Spec and Mil Spec Buffer Tube. What's the Difference?

Posted by Hunter Select on

Choosing Between Commercial Spec and Military Spec Buffer Tubes;
Commercial spec and Military Spec (Mil Spec) parts are almost identical to the human eye that we just have to advise on the difference to our valued customers. One very common AR part that requires such detailed observation between Commercial Spec and Mil Spec is the AR buffer tube.
The Differences between the two specifications;
Again, at first glance, it may seem like a Commercial Spec buffer tube and a Mil Spec buffer tube laying on a workbench next to each other may look like two of the same part, but if one is Commercial Spec, and the other is Mil Spec, then there is enough of a difference between the two to warrant learning more about.
First, a Commercial buffer tube will have a larger outer diameter than the Mil Spec buffer tube; Commercial spec measures at 1.17" outer diameter, with the Mil Spec showing 1.146" on a micrometer caliper.
That is a difference of .024"- enough to not allow interchangeability
between the two buffer tubes as well as the collapsible or fixed stocks normally mated with the buffer tubes. Second, a Commercial Spec buffer tube will also be
angled at the end of the tube, a Mil Spec tube is not. Finally, because the Mil Spec tube's threads are rolled into the cylinder, it's threads appear slightly raised compared to the threads of a Commercial Spec tube which are cut into the cylinder and appear flush with the surface of the buffer tube.
About the origins of the two Buffer Tube Specifications:
The reason for the two different specifications is the cost of manufacturing factor; the commercial spec buffer tubes are threaded differently than its Mil Spec counterpart. The original Mil Spec buffer tubes that were made with early M-16's of the 1960's were roll-threaded, while the more modern commercial spec buffer tubes are threaded by cutting the grooves onto the larger outer diameter tube. Lower cost in manufacturing was the original reason Commercial spec buffer tubes were created.
And the final decision is..
As a result, more people are now faced with the question, should they stay with the original military specifications of the Mil Spec buffer tube when purchasing the part for their AR/M4 build, or try getting with the Commercial specification bandwagon that is out there among other AR/M4 owners? The simplest answer is up to the buyer; it is common to find Mil Spec butt stocks in the firearms market, as well as Mil Spec lower receivers.. the truth is there is greater interchangeability when staying with Mil Spec parts. That is not to say there are fewer choices for Commercial spec buffer tubes when it comes to lower receivers or butt stocks, with lower costs involved in making Commercial spec buffer tubes, there may even be an increase in availability to match that of Mil Spec buffer tubes in the market.
Whichever the buyer chooses to install on their weapon, either Commercial or Mil Spec dimensions, your AR/M4 build will be your personal creation- however you choose to equip your weapon is entirely in your hands.
-Hunter Select

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