I don't see where limiting firearms is going to stop people from killing themselves. If they want to do it, there are a ton of ways. a bullet is probably the easiest and most painless. but high altitudes, deep lakes, long rope, knives, cars, drugs, alcohol, etc etc etc all can be used to take ones life.
Helping our soldiers when they come back should be the first priority. I am going to go out on a limb and say that somebody, somewhere, knew the person who committed suicide had some issues that needed looked at and corrected. Nobody will stop them all, but taking away rights will only enhance the problems.

oh...and don't forget Ft. Hood, where a Taliban supporter was the guy who was therapist supposedly helping our troops get past their problems.