It will be interesting to see how this is applied. On some installations you can already bring on firearms for recreation. Army has a policy that requires registration, you are supposed to declare at the gate and you can only go from your destination (range or hunting) and back out for some installations.
For troops living in the barracks, this will have the most consternation amongst unit commanders. If you have ever had staff duty in the barracks on a Friday or Saturday night, it can be a wild environment. Lots of drunken hijinks occurs, but I think if unit commanders have their staffs do their jobs, it is workable. Troops can still get weapons and sneak on post if they choose to do so, it would just help to lessen the problems of getting jammed up for doing so.
Will have to wait and see how they go about applying this in practicality. I'm sure there are lots of scenarios to work through on this one.