Killed a guy with the M4 yesterday with a leg shot, and shortly after was killed myself with a single shot to the face. My teammate sorted the issue and went to check the bodies. Every single item in my posession was completely destroyed, including all clothing and backpack. All items in jacket/vest/backpack/trousers were ruined and my gun was badly damaged. A quick check of the other victim and the same result, everything ruined.
I'm guessing either theres an issue with the chances of having gear destroyed, or the M4 is secretly firing explosive fragmentation rounds.