Mean Arms Bearing Delay 9mm Luger Complete Upper Receiver

The Bearing Delay Upper Receiver is a complete upper receiver system ready to be paired with the AR lower receiver of your choice. Available in 5 different barrel lengths: 4.5", 7.5", 11", 14.5", 16" - all threaded for a 1/2-28 muzzle device. No 9mm-specific buffer needed. The Bearing Delay Upper Receiver is designed to work with standard AR-15 buffers.

The heart of the Bearing Delay Upper Receiver is the unique ball bearing bolt carrier group (BCG). The ball bearings interface with corresponding features in the barrel extension and provide the lockup in battery and the delay after firing. The system can be tuned by replacing the Lifter to change the angle of the surfaces that push the bearings from the inside of the BCG. The bolt face includes our unique center ejector to provide the most consistent ejection of any 9mm AR on the market. The firing pin passes through the ejector.

Take all the benefits of roller delay: reliability, durability, low recoil and combine with the familiarity of the AR-15 platform. Rollers are obsolete. Each of Mean’s ball bearings has the same contact surface area of the original MP5 roller. So with their 3 bearings, they have 50% more contact surface area than a traditional roller delay. This means that even with the higher pressures of modern ammunition, the Bearing Delay system has greater durability than any roller delay.

The ability to tune the system by swapping the Lifter means that the Bearing Delay system can be tuned based on ammunition type, barrel length, suppressor, or any other factor. Each Bearing Delay Upper Receiver includes two Lifters.

If you elect to use MEAN Arms Endomags (Ejectorless), the Bearing Delay Upper Receiver is compatible with milspec lower receivers OR you can use dedicated pistol magazine lower receivers. Most pistol magazine lower receivers will need to have the stationary ejector removed to be compatible with the Bearing Delay system.

Each Bearing Delay Upper Receiver includes 2 Ejectorless Endomags.

MA Upper Receiver: The Bearing Delay Upper Receiver includes a slick side billet machined aluminum upper receiver that adheres to milspec standards. No forward assist.

MA Handguard: The new MA Handguard is a free float hybrid design including a very rigid high temperature and high strength polymer body with a metallic insert that is overmolded (permanently attached) within the handguard and threads onto the specially designed barrel nut.

SPECS

• Caliber: 9×19mm Parabellum
• Compatible with both milspec AR-15 and dedicated pistol-magazine lower receivers
• Works with standard AR-15 buffers
• Weight of entire Upper (BCG alone is just under 11oz)
• Includes fully tunable ball bearing bolt carrier group, MA Upper Receiver, MA Handguard, MA Charging Handle, MA Muzzle Device, 1 additional Lifter for tuning, and 2 Ejectorless EndoMags.