Yankee Hill Machine Model-57 AR-15 5.56 NATO – Billet Receivers, Nickel-Boron BCG, State-Compliant Featureless Setup
The Yankee Hill Machine Model-57 is a factory-built, billet-receiver AR-15 that pairs precision machining with state-compliant furniture. It features YHM’s signature chevron-milled 7075-T6 receivers, a nickel-boron coated bolt carrier group, and a slick-side upper that deletes the forward assist for a clean profile. Purpose-built touches—like the pinned Magpul MOE stock, featureless fin grip, and 10-round magazines—make this rifle ready for restrictive jurisdictions without sacrificing YHM’s performance standards.
Direct-impingement operation, a 16-inch threaded barrel capped with a YHM multi-prong flash suppressor, and a free-float M-LOK handguard round out a package that is light, accurate, and fully optics-ready. The KC serial prefix indicates a late-production run, giving the buyer one of the newest examples of the Model-57 platform.
Condition
Overall Condition: Excellent – Shows only faint signs of prior use or handling.
Bore Condition: Excellent – Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent – Sharp lands and grooves.
What’s Included
- Yankee Hill Machine Model-57 rifle
- 2 Magpul PMAG Gen M3 10-round polymer magazines
The billet-machined receivers give the Model-57 tight tolerances and a distinctive chevron milling pattern that sets it apart from forged guns. Hard-coat anodizing in matte black protects the 7075-T6 aluminum from abrasion and corrosion.
YHM’s nickel-boron coated bolt carrier group provides a slick surface that resists fouling and simplifies cleaning. Paired with the direct-impingement system, the action cycles smoothly and reliably.
A 16-inch 5.56 NATO barrel, threaded 1/2-28, is topped with YHM’s multi-prong flash suppressor. The muzzle is ready for brakes or suppressors, and the free-float M-LOK handguard offers ample slots for accessories without adding unnecessary weight.
Compliance features include a polymer fin attached to the Magpul MOE grip and a pinned MOE stock that locks out adjustment. These modifications keep the rifle featureless while maintaining ergonomic handling.
The slick-side upper omits the forward assist for reduced weight and a streamlined look. A full-length Picatinny rail remains for mounting optics, iron sights, or night-vision devices as needed.