80% AR9 - S&W 9mm M&P Magazine w/LRBHO - Finger Groove - AR15 Based Lower Receiver - 7075 Raw

$129.99 $109.99
(You save $20.00)
(10 reviews) Write a Review
Calculated at Checkout
Bulk Pricing:
Buy in bulk and save

Sorry, we are Out of Stock

RAW - Finger Groove Front - 80% AR9 - Dedicated S&W 9mm M&P MAGAZINE with LRBHO AR15 LOWER RECEIVER


Q - What does "Dedicate S&W 9mm M&P MAGAZINE with LRBHO" mean?

A - Our lower is designed to accept S&W (SMITH & WESSON) M&P 9mm handgun magazines.  It includes an adjustable last round bolt hold open design (LRBHO) that works with all types of S&W Magazines and is adjustable.  

Q - What is the difference between an AAO 80% lower and others?

A - Integrated Last Round Bolt Hold Open (LRBHO) - Our patent pending LRBHO is adjustable and it functions with all types of S&W Magazines 

   - Safe / Fire is laser etched into the AAO Lower.  

   - ALL AAO Lowers have a built in lower to upper adjustment feature that can be used to take up the slack/space between the upper/lower fitment (via an included allen head screw).  

   - You can quickly test your upper to lower fitment with the AAO Lower before you mill, this is due to a small pocket milled into the rear takedown pin area.

   - High quality and best in class precision machining for a good price.  We are real gun guys and we fire what we make, so it has to be good.

Q - What material do you use?

A - All of our lowers are machined from: 7075-T6 Aluminum

Q - What LRPK (LPK) will work?

A - We recommend the AAO MFG LRPK, however any standard mil-spec LRPK will work.

Q - How does your last round bolt hold open(LRBHO) / empty bolt hold open work?

A - Our patent pending LRBHO is built into the Lower Receiver.  It is reliable, adjustable and works with all of the various magazine types on the market.

Q - Do I need to adjust my LRBHO?

A - Out of the box the LRBHO is adjusted to work with Glock magazines.  See our video on how to adjust for other magazines.

Q - What magazines work in the AAO Lower?

A - S&W M&P magazines 

Q - What bolt carrier will work with this S&W M&P Mag lower?

A - An AR-9 Bolt Carrier that has been cut to clear a Glock Magazine.  On the S&W, we also recommend further clearance of one edge.

Q - Do I need to use a special buffer for my AR-9 build?

A - We recommend using a carbine buffer with a spacer.  The spacer limits the travel of the bolt carrier so it doesn't break the bolt catch. 

Q - Should I adjust my Ejector?

A - We recommend verifying that your bolt cycles without excessive rubbing on the ejector. We also recommend using loctite on the ejector bolts.

Q - What does RAW or "IN THE WHITE" mean?

A - Raw means "unfinished" or "in the white", the unit has been fully deburred and is ready for you to finish.  

Q - What does "Finger Groove Front" mean?

A - Finger Groove Front means that the outside front side of the magazine well area has been machined with Finger Grooves in it.  We also offer a Flat Front machining option for the front side of the magazine well.

Q  - What information do you need if I choose CA Compliance Engraving via the drop down menus?

A - Leave your information in the notes section of the checkout page.

  • CA Compliance list information as follows: Your Name, Your City, State, Multi Cal, Your Serial# 
  • If ordering multiples lowers list your serial numbers as:  0001:0006 (serial number 0001 through 0006)

Q - Do you offer a bulk discount or other discounts?

A - Yes, purchase FIVE AAO Lowers and RECEIVE A 10% DISCOUNT on your lowers.

Q - What calibers can be built with this finished lower?

Smith & Wesson 9mm • S&W 9mm

Q - Is an FFL required to purchase this product?

A - NO, an FFL is NOT REQUIRED to purchase this product.

   - Anyone can legally purchase a 80% Lower Receiver.  An 80% Lower Receiver DOES NOT have to be sold through or registered through a dealer with a FFL (Federal Firearms License).   

Q - What JIG do you recommend to finish the AAO lower?

A - AAO Lowers are compatible with any JIG that will complete a standard Mil-Spec AR Lower.  If you are finishing an AAO 9mm Lower, the Ejector and LRBHO are removable so it can work with any standard Mil-Spec JIG.

Q - What are the operations that must be completed to make the 80% lower fully functional:

A - Machine the following using your JIG to finish our 80 percent AR15 Lower Receiver.  Our 80% Lower Receiver has a fully broached finished Mag Well.   

  • fire control group
  • safety select hole
  • trigger opening
  • trigger pin holes
  • hammer pin holes 
  • The AAO 80% Lower Receiver has been machined to match MIL-SPEC from a 7075 AR15 Lower Forging.

Q - What is a AR15 80% Lower Receiver?

A - 80% lower receivers are parts that have been partially completed.  

   - 80 percent or 80% is a generic term that means that everything is complete on the lower except for the fire control group, safety select, trigger opening, trigger pin holes & hammer pin holes.

   - Utilizing a jig and the right techniques, any 80 percent lower can be quickly transformed into a highly accurate and functional firearm. 

Q - Does a AR15 80% Lower Receiver require transfer or registration through an FFL? 

A - No. This is a do-it-yourself product.. You start with a 80% product and end up with a complete functional product after your finish the machining using your jig. 

Q - Is it legal to do this?  May I lawfully make a firearm for my own personal use, provided it is not being made for resale?

A - This quote is taken directly from the ATF Website http://www.atf.gov/files/firearms/industry/0501-firearms-top-10-qas.pdf: "Firearms may be lawfully made by persons who do not hold a manufacturer's license under the GCA (Gun Control Act) provided they are not for sale or distribution and the maker is not prohibited from receiving or possessing firearms."

Q - Can I build and then transfer a finished firearm to another individual? 

A - Yes you can, however you must mark the firearm in accordance with 27 CFR 472.92 (formally 178.92). You must follow all laws that are in place today. Do yourself a favor an protect yourself, don't put a completed firearm in anyone's hands unless you have gone through proper channels and background checks. Following the proper channels will protect us, our family, and our friends. For any firearm transfer it is your responsibility to understand the federal and local laws and how they apply.  

Q - Is it legal to assemble a firearm from commercially available parts kits that can be purchased via the internet or via Firearms News?

A - This quote is taken directly from the ATF Web Site: "Firearms may be lawfully made by persons who do not hold a manufacturer’s license under the GCA provided they are not for sale or distribution and the maker is not prohibited from receiving or possessing firearms. However, a person is prohibited from assembling a non-sporting semiautomatic rifle or shotgun from 10 or more imported parts, as set forth in regulations in 27 C.F.R. 478.39" https://www.atf.gov/file/61721/download 


Videos Hide Videos Show Videos

10 Reviews Hide Reviews Show Reviews

  • 5
    S&W finger groove with last round bolt hold open

    Posted by Robert on Jul 10th 2019

    This is a great lower. It milled perfectly, and the lrbho works great after I followed the steps in you video to set it. The mag well is sized perfect, because even after cerakote to mag drops free as soon as I bump the mag release. Keep these unique lowers coming!

  • 4
    AR15 S&W mag Lower LRBHO

    Posted by Unknown on Jul 9th 2019

    Everything looks good, it milled just like every other 80% and the mag locks up and drops free easily. The mag is a tiny bit sloppy in the mag well but does NOT fall out. Will buy another!

  • 5
    S&W magazine ar15 80%

    Posted by Nick R on Nov 5th 2018

    S&W ar15 lower!

  • 5
    S&W M&P Lower

    Posted by Bryson T on Oct 29th 2018

    This is a very nice lower. I would recommend to my friends. The bolt hold open feature works perfect.

  • 5
    S&W M&P Magazine lower

    Posted by James C on Oct 26th 2018

    Great quality, quick shipping. Thanks for remembering us M&P guys.

  • 5
    S&W Lower

    Posted by Trey P on Oct 23rd 2018

    Awesome quality and perfect for people like me that prefer the m&p over a glock.

  • 5
    SW magazine lower

    Posted by Andy M. on Oct 6th 2018

    Highly satisfied. Very nice lower.

  • 5
    S&W 9 This thing is freaking awesome.

    Posted by Luke Thompson on Aug 12th 2018

    This thing is freaking awesome. The lrbho is flawless.

  • 5
    S&W lower

    Posted by Ron Mathews on Aug 12th 2018

    I was wanting to build a 40 cal rifle, and when I saw your lower that will let me use my M&P mags, I couldn’t pass it up. I can’t tell you how nice it is to have my pistol and rifle take the same magazine. The last round bolt hold open is super nice. Thanks for a quality product.