What would he change though? I read a stat earlier that 80% of all gun crime in the US is carried out with a gun procured illegally. The only thing Obama could do now is ban guns completely but that won't stop criminals using them, all it will do is make innocent people criminals for wanting to defend themselves.
The US is nothing like the UK or other European countries where the number of guns in circulation is that low you can ban them. In the US there are more guns than people. No matter what Obama tries to do it will not work as criminals are above the law, they do not adhere to it and as such making guns illegal would do nothing.
Imagine the US now where criminals have guns but the innocent also have guns and the right to defend themselves. Now imagine the US where the criminals have guns but the innocent don't because it's illegal to own one, talk about handing the keys to the city to the bad guys. Like I said the US gun system is like no other country, there is little Obama can do. All the individual states can do is to beef up security, but even that has to be done in moderation.