H&K MR556 A4 | 5.56 | 11″ Barrel | 30+1

The Heckler & Koch MR556 A4 is a semi-automatic 5.56 platform built around an 11-inch barrel and a short-stroke gas piston system for consistent operation. It pairs an HK416-style upper with a fully ambidextrous lower and an M-LOK handguard for accessory mounting. For this carbine, a Vortex Strike Eagle 1-6×24 is a capable optic under $1000 that complements the MR556 A4 for close-to-mid range work. Common applications include range training and competition/practical rifle matches.

Product Specifications

• The caliber is .223 REM/5.56 NATO.
• The action is Semi-Auto.
• The barrel length is 11″.
• The capacity is 30 + 1 rounds.
• The weight is 6.61 lbs..
• The overall length is 26.5″.
• The finish is Gray Cerakote.
• The rate of twist is 1-in-7″.
• The receiver is a Fully Ambidextrous Lower.
• The NFA thread pattern is 1/2×28.
• The package includes 1 30 rd. magazine.
• An additional feature is the Short Stroke Gas Piston system.
• An additional feature is the HK416 Upper Receiver.
• An additional feature is the M-LOK Handguard.
• The UPC is 642230272026.

The MR556 A4 is a purpose-built, compact 5.56 carbine that emphasizes reliable operation and ambidextrous control in a compact package. Its short-stroke piston system and HK416-style upper make it well suited for disciplined range work and competition use where quick follow-up shots and modular accessory mounting are valuable. The gray Cerakote finish and ergonomic controls deliver a refined, utilitarian tool that stands up to frequent use.