If he said that, he’s probably way wrong. My guess is he was talking about accidents, not homicides.
The 2009 CDC report shows that of our homicides, firearms are the number one cause of death, with 3.7 per 100,000; all other homicides put together are 1.7 per 100,000.
Contrary to some reports, we have very few accidental firearm deaths (564 in 2009, out of 118,000 accidental deaths).
He was talking about rifles.