Heckler & Koch MR556 A4 5.56mm 11" Pistol - No Brace - 10 Rd

Heckler & Koch MR556 A4 5.56mm 11" Pistol - No Brace - 10 Rd

Engineered for elite performance and built on the legendary HK416 platform, the Heckler & Koch MR556 A4 Pistol (11") delivers uncompromising reliability, precision, and tactical versatility. This semi-auto AR-style pistol is the commercial evolution of HK’s battle-proven design, featuring a short-stroke gas piston system that runs cleaner and cooler than traditional direct-impingement rifles—reducing wear, improving longevity, and minimizing maintenance.

With its fully ambidextrous controls, HK416 upper receiver, and M-LOK handguard, the MR556 A4 is optimized for adaptability and control. The 11" barrel with a 1:7 twist rate ensures tight groupings with 5.56 NATO or .223 Rem rounds, while the threaded muzzle (1/2x28) makes it suppressor-ready. Whether you're building a legally registered SBR or running it as-is, this pistol is a top-tier solution for shooters who demand nothing less than excellence.

Short-Stroke Gas Piston System
Runs cleaner and cooler than direct impingement, reducing carbon fouling and wear.

HK416 Upper Receiver
Military-grade design offers enhanced durability and performance.

Fully Ambidextrous Controls
Includes ambi safety lever and lower receiver for left- or right-handed operation.

Threaded Barrel
11" barrel with 1/2x28 thread pattern is suppressor-ready for tactical flexibility.

M-LOK Handguard
Lightweight and modular for mounting accessories without added bulk.

Enhanced Ergonomic Grip
HK-designed grip improves comfort and control during extended use.

Adjustable Gas Regulator
Tune the action for suppressed or unsuppressed operation with ease.

Compact & Maneuverable
26.5" overall length makes it ideal for close-quarters and mobile applications.

Premium Build Quality
HK’s “no compromise” philosophy ensures top-tier reliability and craftsmanship.

Specifications

• Caliber: .223 Rem / 5.56 NATO
• Barrel Length: 11 inches
• Barrel Twist: 1-in-7", Right-Hand Twist
• Barrel Profile: 6 Lands & Grooves
• Thread Pattern: 1/2x28
• Finish: Black
• Stock/Brace: None
• Magazine Capacity: 10+ 1(Includes 1 Magazine)
• Safety: Ambidextrous Safety Lever
• Grip: HK Enhanced Ergonomic Grip
• Receiver: Fully Ambidextrous Lower
• Upper Receiver: HK416
• Handguard: M-LOK Compatible
• Sights: None (1913 Picatinny Rail)
• Overall Length: 26.5 inches
• Picatinny Rail Length: 16.75 inches
• Weight (Without Magazine): 6.61 lbs