- Machined from 7075-T6 aircraft grade billet aluminum
- Stripped M9 Billet Lower Receiver
- Machined with BETTER than Mil-Spec requirements on state-of-the-art CNC equipment for consistent quality parts and exacting tolerances, dimensions held within +/- .001”
- Matte black hard-coat anodized per Mil 8625 Type 3 Class 2
- Precision machined magazine well with beveled feed lip for easy mag swaps
- Machined and engraved to be compatible with 45- and 60-degree short throw fire control selectors such as our Billet Safety Lever
- Caliber marking of “Multi” so it can be used with different pistol caliber uppers
- Compatible with most standard AR-15 components and most aftermarket parts
- Takedown pin spring and detent hole is threaded for a 6-32 set screw for easy capturing (hardware included)
- Upper tension screw behind grip screw (threaded hole with hardware included) to adjust any “slop” out of vertical fit between upper and lower
- Ambidextrous trigger finger rests with grooves (above and below mag release / mag catch)
- Threaded bolt catch pin (Threaded hole and hardware)
- Integrated large opening “winter” trigger guard
- Proprietary magazine catch assembly and ejector is included and installed at the factory
Save money by building your own AR-9 rifle from the ground up exactly the way you want it configured and shoot for less!
**NOTE – Please read the FAQ below regarding adjustment of your ejector before use and ensure you re-assemble with Loctite or similar thread-locker to prevent screws from backing out over time.
QUESTION: Do I need to adjust my ejector?
ANSWER: Yes, before firing your new pistol caliber lower we suggest you adjust your ejector. Loosen the two screws holding the ejector in to where it becomes a semi-tight friction fit. Ensure the ejector is seated all the way to the rear and all the way down in the pocket. Close your upper onto the lower with the bolt all the way forward. SLOWLY cycle the bolt in and out about 1/4 of the way back a few times then let the bolt close all the way and tighten the ejector screws. They are cupped to get a good grab on the SS ejector, so only hand tight or you risk the chance of bending the ejector over. Any slight rubbing at this point will wear in the ejector after a few magazines are cycled through the gun. If you see excessive rubbing you can also file down the top corner on the left side of the ejector (shooters left). At this point you should remove one screw at a time without disturbing the ejector location and add Loctite to the screws and tighten them back down. This will ensure the screws will not back out over time.
QUESTION: What type of magazines will fit in this lower?
ANSWER: The lower was designed to fit and drop free factory Glock small frame pistol magazines. It has also been thoroughly tested with Magpul GL17 9mm pistol magazines to fit and drop free. Although it accepts and shoots other aftermarket magazines (Promag, KCI, Kahn, etc) some slight modification may be needed to get them to drop free from this lower because of the varying width measurement we have seen when checking these magazines to Glock factory specifications.
QUESTION: Do you offer a reliable last round / empty magazine bolt hold open (LRBHO) System for this lower?
ANSWER: YES — After watching several companies try and fail to incorporate a RELIABLE last round bolt hold open (LRBHO) system into their lower receivers we decided to take a different approach and will be incorporating our LRBHO technology (PATENT PENDING) in our matching upper receivers. After rigorous testing and hundreds of hours of research and development we feel that this is the best option for LRBHO on a Glock magazine AR style firearm. Our upper will be compatible with other manufacturers lower receiver that either don’t have a LRBHO or you can scrap the non-working LRBHO out of your existing AR-9 Glock Mag lower and solve the issue of not having a 100% functioning LRBHO. For more information on our matching AR-9 Upper, please CLICK HERE.
QUESTION: What bolt carrier group will work with a Glock magazine fed AR-9?
ANSWER: You will need an AR-9 Bolt Carrier Group that has relief cuts to clear the Glock style magazines. The AR-9 BCG that we sell (CLICK HERE for AR-9 BCG) will work in both Glock style AR-9s as well as traditional Colt style AR-9s.
QUESTION: What LPK will work with this lower?
ANSWER: Although we sell a specific LPK with just the parts needed to build the M-9 lower receiver HERE, any standard AR-15 LPK will work. You will not need the magazine catch assembly, bolt catch roll pin, or trigger guard that are normally included with standard LPKs.
QUESTION: Do I need to use a special buffer when I build my AR-9?
ANSWER: Although it’s not technically required, it is advised that you either use a 9mm buffer (longer and heavier than carbine) or a spacer in your buffer tube before you place your spring in. The reason for this is to limit the BCG travel to the rear so it doesn’t come back forward and smash the bolt catch hard enough to break it. The 9mm BCG is shorter than a standard BCG. You can use a carbine buffer with a spacer (WHICH YOU CAN PURCHASE BY CLICKING HERE).
The Modern Armory M9 Stripped Billet AR-9 lower receiver is proudly MADE IN THE USA by hard working American men and women.
This is a serialized item considered to be a firearm by BATFE. This item must be shipped to a Federal Firearm License (FFL) holder. All BATFE, GCA & NFA rules apply! This item must be shipped to a Federal Firearm License (FFL) holder. You will be prompted during checkout to pick an FFL to ship to in your area using our FFL Locate tool. YOU will be responsible for checking with your local FFL to ensure this weapon is legal in the state that you reside and that they will accept this weapon on your behalf and transfer it to you. Modern Armory, LLC will NOT be responsible for any shipping or admin charges incurred by packages not being accepted by the FFL you choose during checkout.