I admit, I'm coming from the perspective of a gun-owner, albeit one uneducated in gun related laws, but why not look at countries that already ban, or at least severely restrict the purchasing of, guns. Seems like a logical way to do it without writing up a law that may just have to be repealed if it doesn't help (Something that would be nigh impossible in Congress nowadays).
The difficulty with trying to compare a country that has strict gun control with the US is that most of the countries that have it also have different demographics or a smaller population. That said, the stark contrast to me comes in the rate of firearm deaths between the US and the Uk. The US has a rate of about 10.5 deaths per 100,000 people, while the UK is something more like .25 per 100,000 people. Granted, that is in a smaller population, but the fact is that gun violence occurs less when there are fewer guns.
Sure, and knife violence occurs less when there are less knives, and car accidents occur less with less cars. My point being is that there is less opportunity for less gun violence with less guns. What would be interesting to see is a chart of the ratio of gun violence to gun owners, which I feel would be more accurate.
Many people have looked. The summary I give you will be biased (pro-control, obviously), so why don't you look through #guns here on hubski for articles, or maybe read a bit on the Wonkblog's past few entries if you're interested? That's pretty much what the hashtag system is for. Wikipedia also has some pretty good articles in that direction, shout if you want me to link them.