While I understand the spirit of the OP, I feel it may be a bit premature to assume that this tragedy will bring about stronger anti-gun legislation.
Why? Well, I don't think the fact that a gun was used in this crime will be as large an issue as another issue that will soon come up; Question: How the Hell did someone simply walk into the largest, (and one would assume from that, the most secure facility) the US Army has, with this weapon, without being detected? What role does base security play in this?
I believe that the government is going to have it's hands full trying to come to grips with this issue more so than vilifying guns in general.
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.