When I was in the Army,I knew many fellow soldiers who owned firearms (and carried). Secondly,I can’t see any possible way outside of absolute gross dereliction by the Arms Room that a service weapon is used as a murder weapon. I was always in Infantry so maybe the rest of the services and branches are different.
At ft Riley, I saw some idiot privates pointing empty M9s at each other and pulling the trigger in horse play. ( they had them checked out for cleaning) No NCOs around at that time. But then again they weren’t Infantry either.