Ruger | AR Upper Receiver

Ruger factory AR‑556 parts: buffer‑tube kit (91006), small‑parts kit (90992), M4 stock kit (91007), upper‑parts kit (91005), assembled upper receiver (91003), and stripped upper (91004). These are Ruger AR‑pattern parts for the AR‑556 family, not a complete rifle. Match generation before mixing with a random AR‑15.