AR-9 Pistol Kit (4” Barrel & 5” MLOK Handguard) with 80% Lower (1:10 Twist)



Get ready for ultra short and ultra tactical.  This pistol kit is chambered in 9mm and is well suited for close quarters situations such as home defense.  Plus it’ll turn heads at the range. Mount a tac light on it for things that go bump in the night, and turn this little beastie into the perfect nightstand gun.

Plus, we make it easy for you.  The upper assembly comes pre-built and ready to mount.  Just add backup sights or an optic of your choice. The 9mm lower’s mag well is cut to accept Glock® mags (not included).  Plus, this pistol kit comes with SB Tactical’s SBA3 adjustable pistol brace.  See below for further details.

AR-9 Pistol Build Kit Specs:

Barrel Length: 4″

Barrel Steel: Chrome Moly Vanadium

Barrel Finish: Nitride

Muzzle Thread: 1/2×36

Chamber: 9mm Parabellum

Twist Rate: 1:10

Muzzle Device: Fluted Flash Can

Receiver Material: 6061 T6 Billet Aluminum

Receiver Type: Flat-top w/ Picatinny (Slick Side)

Handguard Type: 5” Lightweight M-Lok

Bolt Carrier Group Included: Yes

Bolt Steel: 8620 Nitride (Heat-Treated)

Charging Handle Included: Yes

AR-9 Pistol Build Kit Features:

  • Complete build kit w/ optional lower
  • Includes pre-built 9mm AR upper
  • High-quality CMV barrel for accuracy
  • Compatible with Glock® magazines
  • Features enhanced, polished trigger
  • Not considered a firearm, no FFL required
  • Proudly built in the U.S.A.
  • Backed by Lifetime Warranty

Barrel: Nitride-coated, 4”, chambered in 9mm Parabellum. Made of 4150 CMV steel. Heat-treated. Features 1:10 twist rate. Includes 5” M-Lok handguard, and fluted flash can.

Upper: Made of 6061 T6 billet aluminum. Hard-coat anodized (Type III).

Bolt: Custom 9mm AR hybrid bolt carrier group. Compatible with 9mm Glock® or Colt SMG magazines. Heat-treated. Nitride finish. 8620 steel.

80% Lower: Complete with optional AR-9 80% lower. Mil-spec fittings. Type III Hardcoat anodized finish.

Lower Parts Kit: Mil-spec 9mm AR lower parts kit. Enhanced, polished trigger (EPT). Six-position buffer tube. SB Tactical Pistol Brace. Carbine buffer spring. 9mm pistol buffer.

Charging Handle: Standard AR-15 charging handle.

Please note: If completing your AR-9 build using the optional 80% lower, please select an AR-9-compatible 80% jig from the available options on our website.

No FFL required  Made in the USA  Lifetime Warranty

Shipping Restrictions

Shipping of various parts and/or accessories are prohibited to states and locales (ie New Jersey, California, New York, etc…) with restrictions against certain parts and/or accessories or “assault weapons” (i.e. states with high-capacity magazine restrictions, manufacturing of semi-automatic weapons, etc..). It is your responsibility to be aware of your local firearms laws before purchasing from our website or machining a firearm. We try our best to keep our shipping page current, but laws change daily only ships within the United States. Federal legislation dictates we cannot ship our products internationally.

We are a national retailer of individual components and not all products depicted on this website are legal in every state. Shipping of various products found on this website are prohibited to some states (such as California, Connecticut, District of Columbia, New Jersey, New York, Rhode Island, and Washington). The information, pictures, text or products presented on this website are not a representation by us, and should not be understood by you, that any product or completed firearm is legal to assemble or own in your state of residence. We encourage each and every builder to perform their own research about the state and federal laws that apply to them. It is your responsibility to understand the law and we encourage you to consult with an attorney or your local ATF representative.