Specifications and Features of the RC-9 Stripped AR-9 Receiver Set:
- Machined from 7075-T6 aircraft grade billet aluminum
- 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 the BAD_ASS ST 45 Lever
- Caliber marking of “Multi” so it can be used with different pistol calibers
- Compatible with most standard AR-15 components and most aftermarket parts
- Take down 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 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 LRBHO in the UPPER
- Proprietary magazine catch assembly and ejector is included and installed at the factory
- Manufactured on state of the art CNC equipment for consistent quality parts and exacting tolerances
**NOTE – Please read the FAQ below regarding adjustment of your ejector before use and ensure you re-assemble with Loctite or similar threadlocker 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 locktite 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 — Many companies don’t offer LRBHO in their lower or if they do, it works poorly. These receiver sets have the LRBHO contained in the UPPER, which uses a simple design to lock the bolt back with the follower of an empty mag. Different brand magazines apply different amounts of pressure to the bolt hold open; This arm can be carefully adjusted to be activated with more or less spring pressure.
QUESTION: What bolt carrier group will work with a Glock magazine fed RC-9?
ANSWER: You will need a Bolt Carrier Group that has relief cuts to clear the Glock style magazines.
QUESTION: What LPK will work with this lower?
ANSWER: Although there are specific LPK with just the parts for a 9mm lower are available, 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 its 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.
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. 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. Roaring Creek Arms LLC will NOT be responsible for any shipping or admin charges incurred by packages not being accepted by the FFL. There is a 35% restocking fee on any firearm you attempt to have sent where prohibited, or which is returned as a result of a refused shipment. See our terms and conditions for more information.