PRO2A 5.5" 40 S&W 1/16 Pistol Caliber NR Side Charging Melonite M-LOK AR-15 Upper Kit with Flash Can
Compact Tactical Performance: Premium Left-Side Charging 40 S&W Pistol Assembly Kit
Transform your standard pistol receiver into a high-powered, low-profile personal defense weapon with the PRO2A 5.5" 40 S&W Complete Side Charging Upper Kit. Built specifically to maximize maneuverability without sacrificing stopping power, this package pairs a ultra-compact 5.5-inch 4150 Chrome Moly Vanadium Melonite barrel with a non-reciprocating left-side charging upper receiver. Engineered to run seamlessly on standard blowback action, this complete kit eliminates assembly friction by including a dedicated 40 S&W Bolt Carrier Group (BCG), a full Lower Parts Kit (LPK), and a fine-tuned heavy buffer system designed for smooth cycling with Glock-pattern 40 cal magazines.
Builder Note: Designed for dedicated AR-40 / AR-9 lower receivers or standard receivers using 40 S&W Glock magazine adapters. Requires an extra-heavy blowback buffer system (included) for optimal cycling speed and reduced wear.
Technical Product Specifications:
- Caliber: .40 S&W (Smith & Wesson)
- Operating System: Direct Blowback (No gas block or gas tube required)
- Upper Receiver Style: Gibbz Arms G9 Style Non-Reciprocating (NR) Left-Side Charging, Billet Aluminum, Hardcoat Anodized Black
- Barrel Length: 5.5 Inches
- Barrel Twist Rate: 1:16 Twist (Optimized for standard 165gr and 180gr .40 cal projectiles)
- Barrel Material & Finish: 4150 Chrome Moly Vanadium (CMV) Steel with Liquid Nitride / Melonite QPQ Finish
- Muzzle Thread Pitch: 5/8x24 TPI
- Muzzle Device: 9/16-24 Extended Slimline Flash Can (Directs blast and concussive sound waves straight downrange)
- Handguard: 7-Inch Free-Float M-LOK Rail System with Integrated Top Picatinny Rail
- Bolt Carrier Group (BCG): Heavy-duty blowback ramped .40 S&W bolt, compatible with Glock style magazine feed lips
- Lower Parts Kit (LPK): Complete Mil-Spec fire control group, safety selector, magazine catch, takedown pins, springs, and standard A2 pistol grip
- Recoil Buffer System: Dedicated heavy blowback 8oz pistol buffer and high-tensile carbine recoil spring
- Platform Compatibility: Standard AR-15 / AR-9 / AR-40 lowers (Glock magazine pattern recommended)
- Origin: 100% Made in the USA
Key Product Features:
- Non-Reciprocating Left-Side Charging Handle: The side-charging lever stays stationary while firing, preventing accidental interference with support hands, optical mounts, or barricades while allowing lightning-fast chamber clear operations.
- Forward-Blast Concussion Shielding: The integrated 5.5-inch barrel paired with a slimline flash can extends slightly beyond the M-LOK handguard to route muzzle flash and intense concussion away from the shooter in tight indoor or vehicle quarters.
- Ultra-Hard Melonite Barrel Coating: The 4150 CMV barrel features internal and external Melonite treatment to resist heat buildup, barrel erosion, and chemical corrosion from high-volume shooting drills.
- Balanced Blowback Recoil Impulse: Comes bundled with a heavy recoil buffer tuned specifically to manage the aggressive pressure spike of the .40 S&W cartridge, drastically reducing bolt bounce and mechanical fatigue.
- Ramped BCG Compatibility: Features an engineered bolt ramp geometry that works smoothly with standard single-stage AR-15 triggers without requiring custom hammer modifications.
Why Choose the Pro2A Tactical 5.5" 40 S&W NR Side Charging Upper Package?
Eliminate Assembly Guesswork and Compatibility Friction
Building a custom pistol caliber carbine (PCC) in .40 S&W often presents timing issues due to component mismatch between buffer mass, bolt weight, and feed ramps. Pro2A Tactical takes the trial and error out of your project by offering a fully harmonized kit. From the feed ramp geometry to the dedicated blowback buffer weight, every item in this system is selected to provide out-of-the-box feeding reliability with both full metal jacket training rounds and jacketed hollow-point defensive ammunition.
Ergonomic Control and Tactical Efficiency
Standard rear T-charging handles on compact AR pistols force you to drop your sight picture or adjust your cheek weld to manipulate the bolt. By incorporating a Gibbz Arms pattern left-side charging handle, your dominant hand stays on the grip and control set at all times. Your support hand naturally cycles the bolt, allowing faster reload cycles, rapid malfunction clearing, and total control during tight movement drills.
Compact Footprint with High-Velocity Punch
The 5.5-inch barrel setup delivers the ideal balance between extreme portability and complete energy transfer for the .40 S&W cartridge. Perfectly sized for backpack carry, home defense setups, or truck gun configurations, this upper kit delivers the stopping power of big-bore handgun rounds with the stability and sight accuracy of a shoulder-braced AR platform.
Sourced from USA Precision Manufacturers
Pro2A Tactical believes in complete component transparency. Our raw materials, barrels, and handguards are sourced directly from established American aerospace and defense manufacturers like Hitman Industries, Kak Industry, and Bowden Tactical. You receive uncompromising build quality backed by real-world performance testing.
Pro2A Tactical Lifetime Warranty Guarantee
Every complete upper receiver group assembled by Pro2A Tactical undergoes strict headspacing and quality checks before shipping. We stand firmly behind our craft with a comprehensive Lifetime Warranty covering defects in materials and craftsmanship, giving you total confidence on the range or in defense applications.
