Sig Sauer SIG556 First-Generation 5.56 NATO Semi-Automatic Rifle, 16" CHF Barrel, JS-Prefix
The first-generation Sig Sauer SIG556 is valued for combining Swiss-inspired design with U.S. manufacture. This JS-prefix example features the early “fish-gill” vented handguards, a cold hammer forged threaded barrel, and an aluminum lower that accepts standard AR/STANAG magazines. Its long-stroke piston system with a 2-position adjustable gas regulator offers reliable, clean operation, making this rifle a sought-after piece for shooters and collectors who appreciate early-run features.
Condition
Overall Condition: Very Good – showing light, superficial signs of prior handling or use.
Bore Condition: Excellent – clean, mirror finish, no signs of wear.
Rifling Condition: Excellent – sharp lands and grooves.
Specific Condition Notes: Minor surface scratches and small blemishes are present but do not affect function or appearance significantly.
What’s Included
- Sig Sauer SIG556 rifle
- 1 polymer 32-round STANAG magazine
- 2 metal 30-round USGI-pattern aluminum magazines
The 16-inch cold hammer forged barrel features a 1:7 twist and factory threading, ready for muzzle devices or suppressors. The adjustable gas regulator lets you tailor cycling for different loads or when running a suppressor.
Early vented polymer “fish-gill” handguards provide distinctive looks and effective heat dispersion. Integrated rails and a scope mount give immediate options for optics and accessories.
The U.S.-made aluminum lower is compatible with widely available AR-pattern magazines, while the collapsible six-position polymer stock allows quick length-of-pull adjustments. A Swiss-style charging handle and integral brass deflector round out the rifle’s practical, user-focused design.
This rifle comes from the earliest commercial production marked “SIG 5.56 NATO,” distinguishing it from later models and underscoring its appeal to collectors tracking first-run variants.