Colt M4 to M5 PDW Upper Receiver Kit 5.56 NATO 10.3" Heavy Barrel CM556-10H-CK – Ultra-Compact Factory Upper Assembly
The Colt M4 to M5 PDW Upper Receiver Kit 5.56 NATO 10.3" Heavy Barrel (CM556-10H-CK) is a genuine Colt factory upper receiver assembly designed to convert a standard M4 lower receiver into a highly compact M5 PDW (Personal Defense Weapon) configuration. This premium upper features a 10.3-inch heavy contour barrel chambered in 5.56 NATO, offering exceptional reliability and durability in one of the shortest factory barrel lengths available from Colt. The heavy barrel profile provides increased rigidity and heat resistance, making this upper ideal for building a true short-barreled rifle (SBR) or compact defensive carbine. Complete with a forged upper receiver, properly headspaced barrel, and optimized gas system, this kit delivers authentic Colt quality and performance for professional, tactical, and enthusiast builds.
Whether you’re constructing a high-end SBR, a professional-grade PDW, or a compact personal defense weapon, the Colt M4 to M5 PDW Upper Receiver Kit offers unmatched factory authenticity and short-barrel performance.
Key Features of the Colt M4 to M5 PDW Upper Receiver Kit
10.3-Inch Heavy Barrel
Ultra-compact 10.3" heavy contour barrel delivers maximum maneuverability while maintaining excellent durability and sustained fire capability.
5.56 NATO Chambering
Chambered in 5.56 NATO for reliable feeding and compatibility with both 5.56x45mm and .223 Remington ammunition.
M4 to M5 PDW Conversion
Factory-designed to transform standard M4 lowers into the ultra-compact M5 PDW configuration used by military and special operations forces.
Why Choose the Colt M4 to M5 PDW Upper Receiver Kit?
When searching for a factory-original ultra-compact upper receiver kit for building a short-barreled 5.56 NATO rifle, the Colt M4 to M5 PDW Upper Receiver Kit (CM556-10H-CK) is one of the most desirable options available. Colt’s reputation for producing military-grade components is well established, and this 10.3-inch PDW upper continues that tradition of quality and precision. The 10.3-inch heavy barrel is the defining feature of this upper. This extremely short barrel length creates one of the most compact AR-platform firearms possible while still maintaining reliable function. The heavy contour adds extra material, increasing barrel rigidity and reducing the effects of heat during rapid fire. This makes the M5 PDW upper particularly well-suited for close-quarters battle (CQB), vehicle operations, and any scenario where a minimal overall length is required. The M4 to M5 PDW conversion allows builders to create a true Personal Defense Weapon platform. The shorter barrel significantly reduces the overall length of the firearm compared to standard 14.5" or 16" carbines, improving maneuverability in tight spaces without sacrificing the proven reliability of the AR-15/M4 system. This upper receiver kit is manufactured to Colt’s strict military specifications. It includes a forged upper receiver, a properly headspaced and contoured heavy barrel, and a gas system specifically tuned for the 10.3-inch barrel length. The heavy barrel profile also provides additional strength for users who plan to install suppressors or other muzzle devices (subject to all applicable federal, state, and local laws). The Colt M4 to M5 PDW Upper is an excellent choice for builders looking to create a high-quality SBR, a professional short-barreled rifle, or a compact defensive weapon. Because it is a genuine Colt product, users benefit from consistent manufacturing quality, proper parts fitment, and long-term durability. This model is particularly well-suited for law enforcement professionals, military personnel, competitive shooters building ultra-compact SBRs, and serious enthusiasts who want authentic Colt components. The combination of the 10.3-inch heavy barrel, 5.56 NATO chambering, and factory M5 PDW configuration makes the CM556-10H-CK a top-tier selection for those seeking maximum compactness and performance. If you’re looking for a premium Colt M4 to M5 PDW Upper Receiver Kit with a 10.3-inch heavy barrel in 5.56 NATO, the CM556-10H-CK delivers the quality, compactness, and reliability that Colt is known for.
- Colt M4 to M5 PDW Upper Receiver Kit
- Chambered in 5.56 NATO
- 10.3-Inch Heavy Contour Barrel
- Forged Upper Receiver
- Factory Gas System
- Black Finish
- Designed for Ultra-Compact SBR and PDW Builds
- Authentic Colt Manufacturing
- Model: CM556-10H-CK | UPC: 098289035486
Technical Specifications – Colt M4 to M5 PDW Upper Receiver Kit
| Specification | Details |
|---|
| Brand | Colt |
| Model | M4 to M5 PDW Upper |
| SKU | CM556-10H-CK |
| UPC | 098289035486 |
| Caliber | 5.56 NATO |
| Barrel Length | 10.3 Inches (Heavy Contour) |
| Barrel Profile | Heavy |
| Upper Receiver | Forged |
| Finish | Black |
| Key Features | Heavy Barrel, M5 PDW Configuration, Ultra Compact |
| Best For | SBR Builds, PDW Platforms, Close Quarters Use |
Shop the Colt M4 to M5 PDW Upper Receiver Kit CM556-10H-CK today.
The Colt M4 to M5 PDW Upper Receiver Kit 5.56 NATO 10.3" Heavy Barrel (CM556-10H-CK) is a factory-original upper assembly featuring a 10.3-inch heavy barrel, forged upper receiver, and M5 PDW configuration. Designed for building ultra-compact, high-performance 5.56 NATO SBRs and PDWs, this premium Colt upper delivers exceptional quality and reliability. Model: CM556-10H-CK | UPC: 098289035486.
The End
