Receiver Materials:
Upper: Billet 6061-T6 Aluminum
Lower: Forged 7075-T6 Aluminum
Buffer Weight(s):
Dedicated 9mm = 5.36oz (Dark grey/black, longer tham Mk4 Carbine buffer)
Bolt Group Materials:
Bolt – Steel, 8620
Extractor – Steel, 4140
Fixed Ejector – Steel, 1070
Virtual Patent Information can be found here.