Glock Compatible Last Round Bolt Hold Open Upper Receiver
With the debut of Aero Precision’s EPC-9 lower receiver, comes the perfect match of an upper receiver. This upper mates perfectly with the EPC-9 lower, preserving the billet-style angles and contours while still being made of forged 7075-T6 aluminum. It looks great, and comes in your choice of matte black anodizing, or a Magpul FDE Cerakote finish.
This upper can be used with most standard AR-15 handguards, and any Glock-compatible Bolt Carrier Group for 9mm or .40 S&W. The Last Round Bolt Hold Open device also ensures that you won’t have to adjust from using your AR-15. No need to rack your charging handle after the last round in your magazine has fired.
What is LRBHO and how does it work?
If you’re used to an AR-15, you might take this feature for granted. Last Round Bolt Hold Open means that when you’re out of rounds, the bolt holds the action open. When this happens, you insert a new magazine, push the bolt release, chamber a round, and keep firing. All of this functionality is contained within the lower receiver on a standard AR-15.
But switching to Glock magazines requires a little workaround, since the bolt catch cannot be engaged by a Glock magazine by default. Aero Precision solved this issue with the LRBHO device integrated into this upper receiver. A steel bar engages with a Glock follower after the last round is fired, which then pushes bolt catch in your lower, and allows your bolt to hold back.
Whether you have a dedicated pistol caliber lower are using a conversion block, this upper will enable you to use LRBHO on your blowback 9mm or .40 S&W rifle.
NOTE: The EPC last round bolt hold open is ONLY compatible with appropriate Glock pattern magazines.
Features
- Last round bolt hold open mechanism
- Accepts most AR15 compatible barrel nuts and handguards
- Dimple above threads to allow for proper handguard timing
- Standard AR15 takedown/pivot pin lug pattern
- Machined from custom forged 7075-T6 aluminum
- Laser engraved T-marks
- Pre-installed last round bolt hold open assembly
Specifications
- Material: 7075 T-6 Aluminum
- Finish: Anodized Black or FDE Cerakote
- Platform: EPC-9
- Weight: 7 oz.
DISCLAIMER: This product is not manufactured, authorized, endorsed, or warranted by GLOCK. GLOCK does not warrant or represent that this product is compatible with GLOCK pistols.
Have Questions About this Product?

The AT3 Tactical store has a 90 day no-hassle return policy for products in good condition. You can view the full details of our return policy here.
If you encounter an issue or defect with a product after 90 days of your purchase, you can refer to the manufacturer for a warranty claim. Their policies are below.
Aero Precision Warranty
If for any reason you have a warranty issue with one of our products, please contact us at 253-272-8188.
Please describe your situation, include your name and order number or transaction id. One of our technical specialists will then review your claim and contact you within 3-5 business days.
If you have images to send, please email them to support@aeroprecisionusa.com
Damaged Items
In regards to claims dealing with damaged or blemished products, we ask that you create a Help Desk Ticket on your My Account page. If you don’t have an account with us, please go to the Contact Us page and fill out the form for review within 72 hours upon receiving the shipment.
If you have images to send, please email them to support@aeroprecisionusa.com
Failed Background Check
There will be a 30% restocking fee on all lower receivers returned because of failed background checks.