CMMG DISSENT Upper Receiver Mk4 5.56x45mm NATO 10.5in 1-7 Twist 1/2x28 Thread Zeroed Blast Compensator Midnight Bronze 55B8D86-MB. 5 DISSENT 5.56 is a ton of fun and its rowdy Now that we got that out of our system our ears quit ringing and we arent...