A precision-focused .300 Blackout complete upper assembly with suppressor-ready adjustable gas system for optimized cycling across suppressed and unsuppressed configurations. Built around a 10.5-inch 4150 CrMoV nitride barrel with front sight base and 1:8 twist rate, this configuration stabilizes bullet weights from 110 to 220 grains across subsonic and supersonic loads. The pistol-length gas system features a premium low-profile adjustable gas block mounted beneath the handguard, allowing shooters to fine-tune gas flow for optimal cycling with both suppressed and unsuppressed fire. The carbine-length quad-rail handguard machined from 6061-T6 aluminum provides extensive four-sided Picatinny rail coverage for lights, optics, and accessories. This complete upper includes an 8620 alloy steel nitride-finished bolt carrier group, mil-spec charging handle, and suppressor-ready 5/8x24 thread pitch for seamless integration with standard AR-15 lower receivers.
This complete upper build includes all essential components for immediate integration with a standard AR-15 lower receiver. The included 8620 alloy steel bolt carrier group features nitride finish for enhanced surface hardness and reduced friction, ensuring reliable extraction and ejection across varying ammunition types. The mil-spec charging handle provides standard reciprocating operation and compatibility with aftermarket upgrades. The premium low-profile adjustable gas block allows shooters to precisely tune gas flow to match their specific shooting conditions—reducing gas flow when running suppressed to minimize blowback and excessive bolt velocity, or opening it up for reliable cycling with unsuppressed fire or adverse conditions. This adjustability makes the Latency complete upper particularly well-suited for shooters who regularly switch between suppressed and unsuppressed configurations.
The 10.5-inch barrel length maximizes powder burn efficiency for .300 Blackout chambering while maintaining a compact, maneuverable profile. The 1:8 twist rate stabilizes bullet weights ranging from 110 to 220 grains, accommodating both high-velocity supersonic loads and quiet subsonic expansion rounds—a critical feature for shooters who leverage .300 BLK's dual-nature capability. The 4150 CrMoV steel construction with nitride finish delivers superior corrosion resistance, enhanced surface hardness, and bore protection, extending barrel life even under the elevated heat and carbon fouling associated with suppressed fire. The included front sight base provides reliable backup aiming capability and co-witnesses seamlessly with modern red dot optics. The suppressor-ready 5/8x24 thread pitch accommodates most .300 BLK suppressors and muzzle devices on the market.
The pistol-length gas system is purpose-built for short-barreled .300 Blackout configurations, featuring a premium low-profile adjustable gas block positioned beneath the handguard—separate from the front sight base. This setup provides optimal dwell time and pressure regulation for this chambering. Combined with the adjustable gas block, this system ensures consistent cycling across the full spectrum of .300 BLK ammunition—from light supersonic loads to heavy subsonic projectiles—while allowing shooters to manage felt recoil, ejection pattern, and gas blowback according to their specific configuration. The upper receiver's M4 feed ramps enhance feeding reliability by guiding cartridges smoothly from the magazine into the chamber, reducing the potential for feeding malfunctions and improving overall function with various ammunition types and magazine configurations—particularly important in defensive and suppressed applications.
The carbine-length quad-rail handguard delivers continuous Picatinny rail coverage on all four sides, accommodating weapon lights, laser aiming devices, vertical grips, and optic risers. Machined from 6061-T6 aluminum, the handguard maintains structural rigidity under recoil while keeping overall weight manageable—an important consideration for suppressor-ready builds where muzzle device and suppressor weight must be accounted for. The four-sided rail configuration provides maximum flexibility for custom accessory placement, allowing shooters to configure the platform for specific mission requirements, whether that's night vision-compatible illumination, close-quarters controls, or precision shooting support equipment.
Follow safe handling practices and manufacturer instructions at all times. Ensure compliance with all applicable federal, state, and local laws. Verify .300 BLK ammunition compatibility and avoid mixing calibers. Confirm proper headspacing and component fitment before firing. Adjust gas block incrementally and test function with chosen ammunition and suppressor configuration.
Upper Receiver: AR-15 Upper Receiver, M4 Feed ramps
Upper Receiver Material: 7075 T6 Aluminum
Upper Receiver Finish: Anodized
Barrel: 10.5-inch .300 BLK Front Sight Base Barrel
Caliber: .300 Blackout
Barrel Length: 10.5-inch
Barrel Material: 4150 CrMoV
Barrel Finish: Nitride
Barrel Thread Pitch: 5/8x24
Barrel Profile: Government, M4 Extension
Barrel Twist Rate: 1:8
Barrel Gas System Length: Pistol Length
Handguard Material: 6061-T6 Aluminum
Handguard Color: Black
Handguard Style: Quad Rail
Gas Block Size: 0.750
Gas Block: Premium Low Profile .750 Adjustable Gas Block
Bolt Carrier: Complete Bolt Carrier Group
Bolt Carrier Material: 8620 Alloy Steel
Bolt Carrier Finish: Nitride
Charging Handle: AR-15 M4 Charging Handle Mil-Spec Quality
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