Most gun massacres have occurred in gun-free zones like schools, malls and, yes, military bases. Thus, the effort to make these zones safer has made them magnets to the crazies. The public is actually safer in concealed-carry states, in nongun-free zones. It is time to look at the facts and correct the flawed thinking of gun-free zones.
The most-useful federal law needed is one to require all gun-free zones to provide armed security. The armed security should be armed adequately to eliminate any threat, which may include visible carrying of assault-type weapons to match the killers. All other areas not designated a gun-free zone should allow concealed-carry and this includes schools, universities, stadiums, malls etc. The idea of allowing properly trained teachers and supervisors in schools to be armed should be considered.
Concentrating on passing more gun-control laws is a waste of time in the USA, as there are millions of all types of weapons including the dreaded assault rifle already out there and there is the Second Amendment.