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Andro Corp Industries Bravo 5.56 NATO Complete Upper Receiver - 10.3" Crane-Spec 4150 CMV Barrel, 9.5" M-LOK Free-Float Handguard, Carbine-Length Gas System, Forged 7075-T6 Receiver, Matte Black Anodized Finish - U556103ML / 736684144555
Product Description
Building a high-performance tactical pistol, staging a Mk18-styled close-quarters combat (CQB) replica, or configuring a dedicated suppressed short-barreled rifle (SBR) requires an upper assembly engineered with tight gas ports. Standard short barrels often suffer from oversized gas ports that flood the receiver with fouling and increase bolt speed, causing premature extraction failures on your bench. The **Andro Corp Industries® Bravo 10.3" 5.56 NATO M-LOK Upper Receiver (U556103ML / 736684144555)** completely flatlines these over-gassing and reliability bottlenecks, delivering a factory-headspaced **CQB barreled upper package** centered around a perfectly tuned 10.3-inch barrel profile.
Proudly assembled, calibrated, and live-fire tested in the United States by Andro Corp Industries, this duty-ready upper receiver is built from a forged **7075-T6 aircraft aluminum alloy** shell finished in a non-reflective Mil-Spec Type III hard-coat anodized layer. Nestled at the mechanical center of the block is a premium **10.3-inch 4150 Chrome Moly Vanadium (CMV) steel barrel** configured with a military standard 1:7 twist rate and an ultra-durable liquid melonite coat. Operating on a robust **carbine-length gas pathway** utilizing a precise 0.070-inch Crane-spec gas port, it yields smooth, predictable bolt cycling whether running unsuppressed duty ammunition or high-backpressure silencers. Wrapped in a low-profile **9.5-inch free-float aluminum M-LOK handguard** with a continuous top Picatinny rail, this turn-key tactical assembly upgrades your custom compact rifle or pistol build straight from your workbench.
Engineered to drop instantly onto standard mil-spec lower receiver pins, this factory-calibrated complete upper assembly ensures absolute reliability directly from your workspace bench.
*Armorer Bench Notes & Real-World CQB Staging Guidance: The Andro Corp U556103ML complete barreled upper assembly arrives workspace ready, containing the pre-machined 7075 upper shell, forward assist assembly, spring-loaded port cover door, 10.3" melonited barrel, low-profile gas block, carbine-length gas tube, 9.5" free-float M-LOK handguard, and a factory-timed A2 birdcage flash hider. MIL-SPEC PIVOT AND TAKEDOWN INTERFACE MATRIX: The lower alignment yokes are engineered natively, strictly, and dimensionally to drop onto **any standard AR-15 mil-spec lower receiver chassis featuring 0.250-inch pivot and takedown pin configurations**. *BCG, Charging Handle, and NFA Completion Checklist:* Please note that this specific SKU is a *barreled upper layout group* and does **NOT include a Bolt Carrier Group (BCG) or Charging Handle** on your bench. Furthermore, attaching this 10.3-inch short-barreled upper package to a standard lower receiver configured with a traditional buttstock creates an SBR, which is subject to strict **NFA registration and tax stamp frameworks** under federal ATF guidelines. Ensure your configuration utilizes a legal pistol stabilizing brace or possesses an approved Form 1 before assembly. Armorer Workbench Custom Staging Sequence: 1. Visually and physically confirm your host lower receiver is completely clear of live ammunition, the magazine is removed, and the fire control area is safe. 2. Apply a thin layer of high-efficiency weapon grease to the outer operational tracks of your separate bolt carrier group and charging handle. 3. Insert the charging handle into the upper receiver tracking slots, drop the bolt carrier array into the cavity, and slide the assembly completely forward into lockup battery. 4. Lay the completed upper receiver structure onto your host lower receiver frame, aligning the front pivot pin holes first. 5. Push the lower receiver\'s front pivot pin horizontally through the upper yoke, pivot the upper down flush, and pop the rear takedown pin home. 6. Pull the charging handle rearward manually several times to verify buttery smooth action cycling and absolute extraction alignment before choosing optics downrange.*
Key Features
- 10.3" 4150 CMV Melonited Barrel: Precision-milled from tough Chrome Moly Vanadium steel alloy and finished with an ultra-hard melonite coat to resist heat erosion and trail wear.
- Crane-Spec Carbine Gas System: Tuned with an optimized gas port size to handle suppressed and unsuppressed tactical ammunition smoothly, preventing over-gassed parts wear.
- 9.5" Slim Free-Float M-LOK Handguard: Features an ultra-lightweight free-float aluminum shroud with M-LOK tracking slots at the 3, 6, and 9 o'clock lanes, isolating the barrel for maximum accuracy.
- Forged 7075-T6 Mil-Spec Receiver: Upper body is forged from high-tensile 7075-T6 structural aircraft aluminum alloy, complete with an integrated forward assist and spring-loaded dust cover door.
- Versatile 1:7 Twist Rate: The heavy-duty rifling twist configuration stabilizes a massive range of tactical and defensive projectiles, ranging seamlessly from 55-grain plinking rounds up to heavy 77-grain duty match ammunition.
- Muzzle Threaded 1/2x28 w/ A2 Hider: The muzzle end is threaded standard 1/2"-28 TPI for easy muzzle brake or suppressor conversion and comes pre-fitted with a factory-timed A2 birdcage flash hider.
Product Specifications
- Brand: Andro Corp Industries® (Winter Garden, Florida / Sourced US Materials)
- Model Line: Bravo Series Complete Factory Assembled Barreled Upper Receiver Systems
- MPN/SKU Code: U556103ML (5.56 NATO 10.3-Inch M-LOK Anodized Black Specification Base SKU)
- UPC Code Profile: 736684144555
- Firearm Lower Frame Compatibility: Standardized Mil-Spec AR-15 / M4 Lower Receivers Natively (0.250" Pin Layout)
- Ammunition Caliber Staging: 5.56x45mm NATO Caliber Chambering (Safely Accepts .223 Remington)
- Total Barrel Length Profile: 10.3 Inches (~261.6 mm Classic CQB / Mk18 Standard Depth)
- Barrel Material Architecture: 4150 CMV (Chrome Moly Vanadium) Steel Alloy Tube Stock
- Barrel Surface Treatment: Complete Liquid Melonite QPQ Matte Black Anti-Wear Hardening Shell
- Rifling Twist Rate Metric: 1:7 Inches Right-Hand Button-Rifled Twist Trajectory
- Gas Operational System Type: Direct Impingement Carbine-Length Gas System Track
- Gas Block Specification Base: 0.750-Inch Diameter Ultra Low-Profile Micro Steel Block (Set Screw Lock)
- Handguard System Profile: 9.5-Inch Aluminum Free-Float Handguard With Perimeter M-LOK Slots
- Muzzle Attachment Interface: 1/2"x28 TPI (Threads Per Inch) Standard Muzzle Thread Track
- Muzzle Device Extension: Mil-Spec A2 Birdcage Flash Suppressor (Timed with Crush Washer)
- Full Kit Component Checklist: 1x Assembled 10.3" Upper Receiver, 9.5" M-LOK Rail, Gas System, A2 Hider (BCG/Handle NOT Included)
- Packaging Format Class: Factory Original Sealed Andro Corp Heavy-Wall Industrial Shipping Container Box
- Product Type Category: Rifle Components / Complete Barreled Upper Receiver Assemblies
- Overall Structural Unit Width: ~2.10 Inches (~53.3 mm Slim Charging Track Clearances)
- Overall Physical Component Length: ~18.55 Inches (~471.2 mm Total Assembled Linear Space)
- Net System Operating Mass: ~2.85 Pounds (~1.29 Kilograms Lightweight Front Balance Base Weight)
- Global Quality Certifications: Formulated to Rigid US Commercial and Professional Duty Staging Standards
- Warranty Tracking Protection: Fully Backed by Andro Corp Industries Factory Product Guarantee
