The debate over gun control has become a battle of talking points.  If you've followed the debate, you've probably heard these lines:

"Forty percent of guns are purchased without a background check."

"There are more people killed with baseball bats and hammers than are killed with guns."

"Barack Obama and Hillary Clinton are negotiating with the United Nations about doing a treaty that will ban the use of firearms."

But those statements, like so many in the gun control debate, are exaggerations or falsehoods. The 40 percent claim earned a Half True on PolitiFact's Truth-O-Meter because it relies on a study nearly 20 years old and uses a relatively small sample. The baseball bat claim earned a Pants on Fire because deaths from handguns alone are more than 12-times higher than clubs and hammers. The statement about the U.N. treaty also got a Pants on Fire because there is no evidence the Obama administration is pursuing such a ban.

With the Senate likely to discuss gun legislation this week, we thought it would be helpful to analyze our fact-checking on the subject. We have examined more than 130 statements about guns and rated more than half to be Half True or lower.  But we've also found that claims about guns fare better on the Truth-O-Meter than claims for all subjects.

Here's how they compare:

We researched the gun control position for each person or group we rated and found gun control opponents have earned more False and Pants on Fire ratings than supporters of gun control:

Our analysis shows that some types of gun claims get higher ratings than others.

When politicians cite their opponents' records on guns, they usually get the facts right and earn a True or a Mostly True. But when politicians or groups make claims about current laws being insufficient -- a common tactic for gun control supporters -- they often earn Half True ratings because they leave out important details or take things out of context.

By contrast, claims about the Obama administration's plans for gun control, often made by people and groups opposed to gun control, typically earn a False or Pants on Fire.