US Contract 5.56mm Piston Complete Replacement Upper Receiver Assemblies for HK416 10.5" Barrel
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US Contract 5.56mm Piston Complete Replacement Upper Receiver Assemblies for HK416 10.5" Barrel

SKU:
67010G01
$1,499.00 $1,299.00
(2 reviews)
Current Stock:
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Description
These US Contract overruns are 5.56mm short stroke gas piston-operated Complete Upper Receiver Assemblies manufactured specifically for the HK416 platform. Built to exact government request these uppers delivers the legendary reliability and reduced maintenance of the HK416’s short-stroke gas piston system in a compact 10.5" configuration. Unlike traditional direct-impingement systems, the piston-driven design keeps fouling, carbon, and heat out of the receiver and bolt carrier group, resulting in significantly cleaner operation, longer service intervals, and superior performance in adverse conditions (dust, sand, suppressed use). This US-made assembly is engineered as a true replacement upper for HK416 rifles (and compatible MR556/MR223 platforms) manufactured by highly capable US manufacturers. It features a high-quality 10.5" barrel, full piston operating system, HK-spec bolt carrier group, and accessory capable handguard. It installs directly onto standard HK416 lowers or mil-spec AR15 lowers with no modifications required. Ideal for military, law enforcement, or serious civilian users seeking HK416-level performance in a compact carbine/pistol configuration. Each unit is test-fitted and function-checked for reliability.
 
NOTE: Gas adjustment knob prevents attachment of a suppressor
 
Key Benefits
  • Short-stroke gas piston system for exceptional reliability and minimal fouling
  • Reduced heat and carbon buildup for extended maintenance intervals
  • Drop-in compatibility with HK416 / AR15 platform lowers
  • US-manufactured to high contract-grade standards
  • Ready-to-install complete assembly
Specifications
Specification
Details
Caliber
5.56x45mm NATO (.223 Remington compatible)
Operation
Short-stroke gas piston (HK416 pattern)
Barrel Length
10.5 inches
Twist Rate
1:7 RH
Chamber
5.56 NATO
Muzzle Device
A2-style flash hider
Gas System
Short-stroke piston, adjustable for suppressed use
Upper Receiver
HK416/MR556 height
Bolt Carrier Group
HK416-spec piston-compatible BCG
Charging Handle
Standard
Finish
Mil-Spec hardcoat anodize (black)
Compatibility
HK416, MR556, and mil-spec AR-15 lowers
Country of Origin
USA (Built to Contract)
 
Included in the Complete Assembly
  • Assembled upper receiver with forward assist and ejection port cover
  • 10.5" piston-ready barrel with gas block and piston/operating rod installed
  • Handguard
  • Complete piston bolt carrier group
  • Charging handle
This upper provides the proven performance of the HK416 system in a compact package while meeting or exceeding US contract manufacturing standards for durability and reliability.
Additional Information
Caliber:
.223/5.56
Barrel Length:
10.5"
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Reviews

  • 1
    Not a 416 contract upper, remotely

    Posted by Matt Andersen on 9th Aug 2026

    Not even remotely a 416 spec’d upper. This thing is a mid level Turkish knockoff. Save your time and money buy something else.

  • 4
    Absolutely suppressible

    Posted by Miguel Ostwald on 7th Aug 2026

    I was getting bored of the HK 416 variance, which I have four including a Haenel. So I decided to take a chance and see what this is about..The fit and finishes excellent. Machining is superb. The internals are compatible with early variance of the 416. Yes you can suppress it! What you need is. B&T NATO A2 Flash Hider 5.56 1/2x28 SD-145138 and a can with a B&T A2 NATO hub adapter. Wawa it’s suppressible. The only thing that sucks is the proprietary Picatinny rail sections. I’m gonna see if LWRC rail sections work. Cool toy.