I kept my gun's at my parents house while I was in the service- not only can you not keep them in your home/dorm on base (they go into the base armory), the people in charge of the armory tend to take whatever gun out (assuming you don't lock it in a case or with a trigger lock) they feel like and shoot them, and put them back up dirty. I saw this happen several times with coworkers and friends, but they still wouldn't get locks for some reason.
Yet, augmentees to the security police/gate guards are rocking full M-16s, who haven't touched a rifle since basic training, and only have a limited knowledge of the job (they are filling in for deployed folks form other careers fields).
And some bases are huge, it might take military police just as long to respond as civilian LEOs.
One of the many disconnects I remember from my time in service - we put you in charge of millions of dollars of equipment - but we have to inspect your dorms weekly to make sure you don't have dust on your lampshade.
EDIT: Don't get me wrong, I loved my time in the service - but it's still full of people, and people sometimes make silly decisions and flat out make mistakes.
Why is this something only the Army is letting people know about? Air Force, and other branches are just as at risk. My wife, a military brat, did not know that military people on base don't have guns. I think the public needs to know that military bases are essentially gun free zones. Last time I entered a base I couldn't even carry a pocket knife. People in general think of the military as carrying automatic weapons, rocket launchers, etc. But in reality they are probably the least armed people on American soil unless they are MPs. Correct me if I am wrong.