A single missing M4 is “a serious security risk”? OK dude.
I was a member of the 25th Infantry from 1978 until 1981. They had the US Army’s record for most lost weapons.
My unit was “fighting” against a Marine unit. The Marines attacked another unit not involved in our training and a brand new Army private panicked and dropped his M16. A Marine stole it, hid it and returned later to get it. The police found the M16 about 6 months later during a raid on a drug house. Yes, it had been traded for drugs.
Missing weapons were taken deadly seriously in the US Army I remember..