From the Daily Kos:
Since the end of the Reagan administration, more Americans have been killed by guns than have died in battle while serving in the U.S. military in the entirety of U.S. history. It isn't close. In fact, the time scale of the U.S. military deaths begins at the beginning of the Revolutionary War, which was actually before the United States was officially founded.
The chart comes from a report (pdf) by the Center for American Progress Action Fund, titled:
Right of Reagan How the Extremism of Today’s Republican Presidential Candidates Sets Them Apart from Their Conservative IdolThe report contains a wealth of important and disturbing information, and this is just one example. Reagan once was considered on the far right fringe, and although he did usually side with the NRA he also supported the Brady Bill, and explicitly supported background checks and an assault weapons ban. Compared to the modern Republican Party, he was a hippie liberal.