HK416 Parts group with 80% lower

Upper receiver and barrel assembly

• Upper receiver
• Hex Boron Treated 4150V Chrome Moly Vanadium (CMV) Barrel (cold-hammer-forged, chrome-lined; lengths commonly 10.4″, 11″, 14.5″, 16.5″, or 20″)
• Barrel nut
• Flash hider / compensator
• Gas block (multi-function: front sight interface, sling points, bayonet lug, grenade-launcher interface on many models)
• Gas piston and piston rings
• Piston rod assembly
• Free-floating rail system (FFRS / handguard) with locking screw and retaining spring
• Ejection port cover assembly (cover, spring, pin)
• Forward assist
• Charging handle assembly
• Optional folding front sight and rear diopter sight

Bolt carrier group

• Bolt carrier
• Bolt
• Cam pin
• Firing pin, firing-pin spring, and retaining pin
• Extractor and extractor spring
• Ejector and ejector spring

Lower receiver and fire-control group

• 80% Lower receiver
• Pistol grip and grip screw
• Trigger, hammer, disconnector (and associated springs/pins)
• Fire-control selector / safety lever and detent
• Trigger guard
• Magazine catch / release assembly
• Bolt catch / release assembly
• Pivot pin and takedown pin (with springs and detents)
• Buffer retainer

Buttstock and recoil system

• Receiver extension (buffer tube)
• Recoil spring / buffer
• Castle nut and end plate
• Sliding / collapsible buttstock (with release lever and sling swivel)