Gemtech GVAC Upper Receiver | 5.56 NATO | 16.10″ | 13833

The Gemtech GVAC upper assembly is a 5.56 NATO AR-style upper built around Gemtech’s GVAC system to reduce gas blowback when shooting suppressed. It pairs a 16.10″ GVAC-profile barrel and a pinned mid-length GVAC gas block with a Gemtech ETM flash hider and a 15″ Midwest Industries M-LOK free-float handguard. This upper ships with a bolt carrier group included; it does not include a charging handle.

Product Specifications

• The manufacturer is Gemtech.
• The model/MPN is GVAC Upper (MPN 13833).
• The caliber is .223 REM/5.56 NATO.
• The barrel measures 16.10 inches with a GVAC profile.
• The rate of twist is 1:8.
• The barrel steel is 4150CMV steel, stress relieved and is Armornite treated.
• The muzzle threads are 1/2×28 TPI.
• The gas system is a pinned low-profile mid-length GVAC gas system (direct-impingement).
• The muzzle device is a Gemtech ETM flash hider.
• The bolt carrier group is Carpenter 158 bolt with an 8620 carrier and includes mag-phos finish and chrome-lined components.
• The upper receiver is 7075-T6 aluminum, Type III hard coat anodized and includes M4 feed ramps.
• The handguard is a 15-inch Midwest Industries Combat free-float M-LOK with a continuous MIL-STD-1913 top rail and integrated QD sling sockets.
• The external finish is Armornite (black).
• The NFA thread pattern is 1/2×28.
• The UPC is 022188894615.

Engineered for reduced gas blowback when used with suppression, this GVAC upper is suited to suppressed range training and precision/competition applications where consistent gas behavior and reliability matter. The combination of a stress-relieved 4150CMV barrel, enhanced BCG components, and a free-float M-LOK handguard makes it a practical choice for shooters seeking an upper optimized for suppressed use and repeatable performance.