SIG Sauer SIG 556 Gen 1 5.56 NATO Semi-Automatic Rifle with AGP Folding Stock, Swiss-Pattern Lower, 16" CHF Barrel
This first-generation SIG 556 pairs classic Swiss SG 550 lineage with U.S. manufacture, offering a long-stroke piston system, adjustable two-position gas block, and the early “JS” serial prefix prized for its higher Swiss parts content. An AGP Arms polymer side-folding stock adds compact versatility, while the cold-hammer-forged, chrome-lined 16-inch barrel brings durability and accuracy in a lightweight profile.
Condition
Overall Condition: Good condition, showing some signs of prior use and handling.
Bore Condition: Excellent – Clean, mirror finish, no signs of wear.
Rifling: Excellent Rifling – Sharp lands and grooves.
Specific Condition Notes: The exterior shows scattered surface scratches and handling marks consistent with normal use. The bore is bright and free of fouling.
What’s Included
- Rifle
- 3 × 30-round proprietary SIG Sauer 55X-pattern polymer magazines (rock-and-lock style)
The rifle’s cold-hammer-forged, chrome-lined barrel is threaded 1/2-28 for easy attachment of muzzle devices or suppressors. Combined with the lightweight contour, it balances well for rapid handling without sacrificing longevity.
The stamped-steel upper receiver and hard-coat anodized alloy lower wear a matte grey Nitron-type finish that complements the polymer fish-gill handguard. Removable tri-rail panels let you mount lights, lasers, or vertical grips while retaining the original Swiss look.
An ambidextrous safety selector, press button-style magazine release, and scope rail deliver modern ergonomics. The flip-up front sight on the gas block provides a reliable backup aiming option when optics are installed.
Custom touches include the AGP Arms polymer side-folding, skeletonized stock, giving the rifle a compact footprint for storage or transport without adding weight.
Discontinued in 2017, early-run Gen 1 examples like this remain sought after by collectors and shooters who appreciate the blend of Swiss design and American production.