You must read the comments on the Yahoo article: White House slams NRA ad using Obama daughters to criticize new gun laws. Most of the comments go one way. This way:
Out of 300,000,000 guns in the US, about 8,000 are used to murder someone each year. This mean that out of all the guns in circulation only .00002666666% of the guns are used in homicides.
I have never seen the comments on Yahoo so pro-gun. People are angry. I don’t have the information on whether the above quote is accurate, but just spit-balling it, it sounds accurate.