Geissele Super Duty SD-556 5.56 NATO AR-15 Rifle – 16" CHF Barrel, MK16 Rail, Ambi Controls
The Geissele Automatics Super Duty SD-556 brings duty-grade reliability to the AR-15 platform, pairing a cold-hammer-forged, chrome-lined 16-inch barrel with Geissele’s mid-length-plus gas system and Nanoweapon-coated Reliability Enhanced bolt-carrier group. A flat-faced SSA-E X two-stage trigger, Airborne ambidextrous charging handle, and MK16 15-inch handguard modeled after the USSOCOM URG-I make this rifle stand out for shooters who demand hard-use durability and refined shootability.
Condition
Overall Condition: Excellent – Shows only faint signs of prior use or handling.
Bore Condition: Excellent – Bright, mirror finish with sharp lands and grooves.
Specific Condition Notes: The rifle displays minimal handling marks; the bore remains clean and crisp.
What’s Included
- Magpul AFG polymer angled fore-grip (installed)
- Stubby vertical fore-grip (installed)
- Polymer flip-up front and rear back-up iron sights (installed)
- 1× 40-round Magpul PMAG magazine
- 1× 30-round Magpul PMAG magazine
Geissele builds the Super Duty SD-556 around a 7075-T6 forged receiver set with a flared mag-well and integral trigger guard, finished in durable black anodizing. Ambidextrous controls—safety selector, mag release, charging handle—make the rifle equally accessible to right- or left-handed shooters.
The 16-inch, 1:7-twist barrel is cold-hammer-forged, chrome-lined, and tapered for balanced weight. It is threaded 1/2-28 for muzzle devices and fed by Geissele’s proprietary mid-length-plus gas system for smooth recoil management.
A 15-inch Super Modular Rail MK16 handguard, machined from 7000-series aluminum, offers full-length M-LOK slots and shares its design with the USSOCOM URG-I program. The rifle’s two-stage SSA-E X trigger provides a light, precise break while retaining duty-ready safety margins.
The Nanoweapon-coated Reliability Enhanced BCG and Stressproof bolt contribute to exceptional wear resistance and extended service life, underscoring Geissele’s focus on battlefield durability.