I would have thought that since 9-11, security at military installations would have been more strictly monitored than back in the 80's when I was in, and I can assure you that it would have been almost impossible to have brought a weapon in to any of the AFB's I was stationed at.
I live right next to WPAFB. I went to a school with a lot of AF kids and many teachers were spouses of AF personnel/contractors. I was able to get onto base several times without correct paperwork between 2001 and 2003. Mostly in a vehicle through a CP. When I entered with kids from my HS our car was only searched once and that a day following us entering the gate in boxers only b/c there was a cute guard on duty and we thought it would be funny. I assume the two occurrences were related.
I think this guy just cracked. I have heard indications that 8 years of treating soldiers who have PTSD, depression,etc. has had a toll on the Psychiatric staff in the military, just like 8 years of IED amputees/burn victims has had a toll on the medical staff.
I think the direction this event will be taken will be that the military is spread thin and we are pushing it too hard in "lost wars overseas", not for gun control. I view it as an indication of being spread thin/worn down, I won't make a judgment as to whether the wars are lost or not.