G36 KV1 HK G36 KV adjustable stock HK G36 5.56x45 318mm barrel HK G36 5.56x45 4-prong flash hider HK G36 gas block HK G36 4-vent handguard HK G36 hand stop HK G36 magwell HK G36 Hensoldt HKV 3x carry handle Hensoldt RIS top rail G36 KV2 HK G36 KV adjustable stock HK G...