Progressive Change Campaign Committee has launched a new ad criticizing Senate Republican Leader Mitch McConnell over proposed gun control measures.This is the second spot by the group to target McConnell, and like the previous ad it features a Kentucky gun owner and military veteran who supports a ban on assault weapons.Watch:The McConnell campaign has criticized the group for taking contributions from liberal billionaire George Soros and says the GOP leader is a "stalwart" defender of the Second Amendment.UPDATE:As Pure Politics points out, McConnell has balked on whether he would back a ban on semi-automatic firearms. But his voting record shows he has opposed more regulations.