9mm AR Components
Similar to the AR-15, an AR-9 can be assembled from various parts, and many of the elements that constitute the AR-9 are compatible with AR-15 parts. Nonetheless, there are essential distinctions to take into account. Here is a summary of several key elements of the AR-9:
Components of the AR-9 Upper.
Upper Receiver: The AR-9 upper receiver is essential, determining a significant portion of the firearm’s overall performance. It utilizes the same military-spec upper found in AR-15 constructions, making the assembly largely similar, with components such as the handguard, barrel nut, and charging handle identical for both systems.
You can either assemble an upper from components, or you can purchase a fullycompleted one made by a manufacturer. Bothoptionsare a goodpath to follow, but if you intend to create one, remember that it can entail a significant learning curve if you lack prior experience with the process. Our guide for putting together an AR-15 upper serves as an excellent resource to assist you in beginning.
Barrels: AR-9 barrels resemble AR-15 barrels, utilizing comparable contours and forms. Nonetheless, AR-9 barrels do not include a gas port because they operate using a direct blowback mechanism, which makes a gas block and tube unnecessary. When constructing your upper, there’s no requirement to select a gas block, unless you’re replicating the original Colt SMG. Additionally, these barrels are equipped with threads for muzzle devices, though the thread pitch may differ based on the manufacturer. Typically, AR-9 barrels have a thread pitch of ½-36.
BCG: The AR-9 bolt carrier group differs from the typical AR-15 BCG. Engineered for the direct blowback mechanism, it features a one-piece design instead of several components, as there’s no requirement for a locking and rotating bolt. While most AR-9 BCGs feature a similar single-piece construction, various versions exist that offer unique benefits.
A well-known AR-9 BCG is the radial delay blowback system, also called RDB, produced by CMMG. It employs a collection of radially shaped bolt lugs to form a mechanical delay to ensure a safer and more reliable operation.
Lower AR-9 Components
Lower Receiver: AR-9 lower receivers haveundergoneconsiderabledevelopment. Initial AR-9 versionsutilized a magazine adapter installed in a mil-spec AR-15 lower, whereascontemporary AR-9 lowers are engineered to accommodateparticular magazine designs.
Magazines compatible with GLOCK are the most frequentlyutilized in current AR-9 models sincethey are easilyobtainable, with numerous extended options of 30 and 33roundsalso available, making AR-9s and 9mm GLOCK handguns an excellent pistol and rifle combination. Alongside GLOCK pattern lowers, Colt pattern lowers remain extremely popular. These lowers utilize the original Colt SMG pattern magazines, which are not as commonly available as GLOCK-compatible magazines; however, surplus magazines and contemporary reproductions from brands such as Duramag are easily accessible.
Numerous essential parts, including the trigger group, safety selector, grip, buffer tube, and various internal components, are identical to those found in AR-15s. The buffer weight might require replacement to function properly in an AR-9, but several manufacturers offer specific AR-9 buffer kits to simplify the process of selecting the correct one.
Similar to constructing an upper, creating an AR-9 lower is fundamentally like building one for an AR-15. If this is new ground for you, we suggest looking at our detailed guide on assembling a lower receiver before you dive too deep into your project. Check our category page, 9mm AR pistols for sale.
