HK MR556A1 Competition 5.56 NATO Rifle, 16.5 in CHF Heavy Barrel, Piston System, Extended MRS HKey Rail, SIG TANGO-MSR 1-6x24, 6 Mags, Case
This Heckler & Koch MR556A1 Competition is the HK416-derived, short-stroke gas piston variant built for durability and control. It features a 16.5 in cold hammer forged heavy-profile barrel with a 1:7 RH twist, an extended 14 in free-float MRS HKey handguard with a continuous top rail, and a multi-chamber spiral-ported compensator/brake. Dated 2018 by the upper receiver BI code, it comes configured with a SIG Sauer TANGO-MSR 1-6x24 LPVO in a SIG cantilever mount, six 30-round magazines, and a Savior Equipment soft rifle case.
Condition
Overall Condition: Very good condition, showing only light, superficial signs of prior handling or use.
Bore Overall Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: Minor superficial scratches and small blemishes are visible on exterior surfaces upon close inspection.
What's Included
- Savior Equipment soft rifle case (tan)
- SIG Sauer TANGO-MSR 1-6x24 LPVO (installed) with SIG flip caps
- SIG Sauer cantilever scope mount, 30mm, 1.535 in height, P/N S0A20014, marked 65 in-lb (installed)
- Magpul AFG angled foregrip (installed)
- QD sling socket installed in handguard (no swivel included)
- Six 30-round magazines (mix of Magpul PMAG polymer and aluminum STANAG-pattern)
The MR556A1 Competition draws from HK416 lineage and uses a semi-automatic, short-stroke gas piston system with a rotating bolt. Controls include a manual safety with HK pictogram markings on both sides and a 30+1 capacity. The rifle carries the HK logo and model text “MR 556 A1 COMPETITION 5.56 mm x 45” on the left magwell, with the bolt carrier marked HK and MR.
The 16.5 in barrel is cold hammer forged, heavy profile, and unlined, with a 1:7 RH twist to stabilize a broad range of 5.56 NATO projectiles. It is threaded and fitted with a multi-chamber, spiral-ported compensator/brake to aid in muzzle control. The bore presents a clean, mirror finish with sharp rifling.
Designed for competition use, the platform features an extended 14 in free-float Modular Rail System (MRS) handguard with HKey interface and a continuous top rail. Factory configuration shipped without iron sights. This example is outfitted with a SIG Sauer TANGO-MSR 1-6x24 LPVO and a SIG 30mm 1.535 in cantilever mount, plus SIG flip caps, delivering a ready-to-run sighting setup.
Ergonomics and handling are supported by a 6-position adjustable polymer stock and an installed Magpul AFG angled foregrip. A QD sling socket is installed in the handguard for quick attachment; swivel not included. Overall length is approximately 33.75–37.00 in with an approximate weight of 8.81 lb (with empty polymer magazine. Length of pull is approximately 10.5–14.0 in.
Markings and provenance details include the upper receiver date code BI (2018) and a right-magwell import mark reading Heckler & Koch Inc., Columbus GA. This Competition configuration pairs HK’s piston-driven operating system and heavy-profile barrel with an extended handguard and competition-focused controls.