Heckler & Koch MR556A1 5.56 NATO Semi-Auto Rifle, HK416-Derived, 16.5 inch CHF Heavy Barrel, Piston-Driven, M-LOK Handguard, HK E1 Stock, Magpul MOE-K2 Grip
The HK MR556A1 is a semiautomatic, short-stroke gas piston rifle derived from the HK416 and built with AR-15 pattern controls. This example features a 16.5 inch cold-hammer-forged heavy barrel with a threaded muzzle, HK's free-float aluminum M-LOK handguard, and the HK E1 adjustable stock. It includes German CIP proofing and a CC two-letter date code on the upper, and is fitted with a Magpul MOE-K2 pistol grip. The rifle has a continuous Picatinny top rail with no sights installed.
Condition
Overall Condition: Very good condition, showing only light, superficial signs of prior handling or use.
Bore Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: There are some minor scratches and blemishes visible from prior handling.
What’s Included
- Two 30-round magazines
- HK-branded soft rifle case
- Manual
- HK-branded folding hex key tool
Built on HK's short-stroke gas piston system, the MR556A1 delivers clean operation with familiar AR-15 style controls. It includes an ambidextrous safety with selector pictograms, a standard right-side magazine release, and an HK-marked bolt carrier. A forward assist, ejection-port dust cover, and case deflector are all present.
The 16.5 inch cold-hammer-forged heavy-profile barrel uses a 1:7 RH twist and an unlined bore, optimized for durability and performance. The threaded muzzle is fitted with a birdcage flash suppressor.
HK's free-float aluminum M-LOK handguard includes an integral QD sling socket and a removable, numbered top rail segment. A continuous Picatinny top rail runs from receiver to handguard, and there are no sights installed.
Furniture includes the HK E1 stock with six-position adjustability, a textured rubber buttpad, and a length of pull adjustable from 11 to 14 inches. A Magpul MOE-K2 pistol grip is installed. The hard-anodized aluminum receivers carry a German CIP proof mark and CC date code on the upper, with Heckler & Koch Inc., Columbus, GA receiver marking.
The rifle accepts STANAG pattern magazines and has a stated capacity of 30+1. The hard-anodized finish and aluminum receiver construction provide a robust, duty-grade exterior.