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Are you at least 18 years old?
Are you at least 18 years old?
Unlock enhanced velocity, extended range, and precise shot placement with the PRO2A 18" 5.56 NATO Mid Length Melonite M-LOK Upper Kit. This 100% American-made master build bundle contains every critical component required to transform a standard stripped lower receiver into a finished tactical asset. Built around a premium 18-inch 4150 CMV steel barrel, this kit features a highly versatile 1:8 twist rate engineered to stabilize a wide range of projectile weights with exceptional consistency. Complete with a pre-headspaced M16 bolt carrier group, standard charging handle, complete lower parts kit (LPK), and a matching 6-position carbine buffer stock assembly, this all-inclusive package takes the guesswork out of building your next multi-purpose rifle.
| Upper Receiver Assembly | Mil-Spec Forged 7075-T6 Aluminum, M4 Feed Ramps, Forward Assist & Port Cover, Type III Hardcoat Anodized Black Finish |
|---|---|
| Bolt Carrier Group | Full M16 Profile, Heavy-Duty 9310 Steel Bolt Face, Nitride Finish, 8620 Carrier, Properly Staked Gas Key & MPI Tested |
| Charging Handle | Standard Mil-Spec Aluminum Charging Handle Assembly |
| Barrel Component | 18 Inch Profile, 4150 Chrome Moly Vanadium (CMV) Steel, Medium Contour, Melonite Treated Interior & Exterior Bore |
| Caliber | 5.56 NATO (Accepts .223 Remington) |
| Twist Rate | 1:8 Twist |
| Gas Operating Block & System | Mid-Length Gas System, Low-Profile Gas Block Machined from 4140 Steel, Stainless Steel Gas Tube |
| Muzzle Device Component | Standard 1/2x28 Thread Pitch, A2 Birdcage Flash Hider with Crush Washer Pre-Installed |
| Handguard Rail | 15 Inch Slim Profile Free-Float Aluminum Handguard, Continuous Top Picatinny Alignment, Modular M-LOK Attachment Points |
| Lower Receiver Parts Kit (LPK) | Complete Mil-Spec Spring and Pin Kit, Polished Single-Stage Hammer and Trigger Assembly, Standard A2 Pistol Grip |
| Carbine Buffer Stock Extension | Adjustable 6-Position M4 Stock, Mil-Spec Diameter Buffer Tube, Standard 3oz Carbine Buffer, and High-Tensile Buffer Spring |
| Manufacturing Origin | 100% Assembled and Quality Checked in the USA with Pro2A Tactical Lifetime Factory Warranty |
Piecing together a precision rifle build from separate sources often introduces compounding tolerances, leading to headspacing headaches, short-cycling issues, or poor accuracy. The PRO2A 18" 5.56 NATO Upper Kit directly bypasses these frustrations. Every component in this master package—from the hand-assembled free-float upper to the lower receiver internal springs, buffer weight, and bolt carrier group—is pre-selected and optimized to interface perfectly out of the box. Offering the added muzzle velocity of an 18-inch barrel paired with a highly adaptable 1:8 twist rate, this complete build bundle is the ultimate way to achieve reliable, long-range performance without paying individual part premiums.
| SKU | P2A556GFS15MID18-TK-KIT |
|---|---|
| Barrel Length | 18 inch |
| Rifle Caliber | 5.56 NATO |
| Manufacturer | Pro2A Tactical |
