Demand for Last Round Bolt Hold Open (LRBHO) AR platforms continues to grow. Moriarti Armaments has restocked a limited selection of Last Round Bolt Hold Open (LRBHO) pistol uppers, complete pistols, and rifles in some of today's most popular pistol-caliber AR chamberings:
- 9mm
- 10mm Auto
- 40SW
- .45 ACP
If you've been waiting for an LRBHO AR upper, complete PCC pistol, or rifle, now is the time to check current inventory. Quantities are limited, and popular barrel lengths and configurations may sell through quickly.
Why Shooters Choose LRBHO
A Last Round Bolt Hold Open (LRBHO) system automatically locks the bolt to the rear after the final round is fired.
Shooters often prefer LRBHO because it provides:
- Faster reloads
- Immediate indication of an empty magazine
- Familiar AR-style operation
- Improved training consistency
- Added convenience for range and competition use
LRBHO remains one of the most requested features in modern blowback AR platforms.
Back in Stock: 9mm, 10mm, 40SW & .45 ACP
Current Moriarti inventory includes select configurations across multiple PCC calibers.
9mm LRBHO
The 9mm AR remains one of the most popular pistol-caliber AR platforms thanks to manageable recoil, broad ammunition availability, and strong aftermarket support.
Available configurations may include:
- 9mm LRBHO pistol uppers
- Complete 9mm AR pistols
- 9mm PCC rifles
10mm Auto LRBHO
For shooters seeking increased energy from a pistol-caliber AR, 10mm Auto delivers impressive performance while retaining the familiar ergonomics of the AR platform.
Select LRBHO configurations may include:
- 10mm pistol uppers
- Complete 10mm AR pistols
- 10mm PCC builds
40SW LRBHO
The 40SW AR platform offers a balance of controllability, reliability, and pistol-caliber performance.
Available inventory may include:
- 40SW LRBHO uppers
- 40SW AR pistols
- PCC rifle configurations
.45 ACP LRBHO
The AR-45 brings the proven .45 ACP cartridge into a modular AR platform.
Select inventory may include:
- .45 ACP LRBHO uppers
- Complete AR-45 pistols
- .45 ACP PCC rifles
Built for Blowback AR Platforms
Moriarti LRBHO products are designed around dependable blowback operation and compatible magazine systems.
Proper performance depends on the complete setup, including:
- Correct bolt
- Compatible magazines
- Appropriate buffer weight
- Quality recoil spring
- Properly matched upper and lower components
Limited Inventory
Current LRBHO inventory is available in limited quantities and may vary by caliber, barrel length, handguard, and configuration.
If you've been waiting for a 9mm, 10mm, 40SW, or .45 ACP LRBHO platform, this restock is a good opportunity to secure the configuration you want before the next production run.
Frequently Asked Questions
What calibers are currently available in LRBHO configurations?
Current inventory may include 9mm, 10mm Auto, 40SW, and .45 ACP LRBHO pistol uppers, pistols, and rifles. Availability varies by configuration.
What does LRBHO mean?
LRBHO stands for Last Round Bolt Hold Open. The feature automatically locks the bolt to the rear after the final round in the magazine is fired.
Are both complete firearms and upper assemblies available?
Yes. Moriarti has restocked select LRBHO pistol uppers, complete pistols, and rifles.
Does LRBHO improve reliability?
LRBHO is primarily a convenience and handling feature. Overall reliability depends more heavily on proper bolt, buffer, spring, magazine, and ammunition compatibility.
Are quantities limited?
Yes. This is a limited restock, and popular calibers and configurations may sell out quickly.
Shop current LRBHO inventory in 9mm, 10mm Auto, 40SW, and .45 ACP while supplies last.
