Definition of what’s actually an 'assault weapon' is a highly contentious issue
  • Exactly what constitutes a so-called "assault weapon" is a highly contentious issue and something that riles up some gun advocates.

  • Some gun control backers pushing for an assault weapons ban include the AR-15-style rifle used in recent mass shootings.

  • But the firearms industry insists the AR-15-style rifles are technically neither assault weapons nor assault rifles.

Following last week's Florida school killings, there's movement by gun control advocates in some states to ban so-called assault weapons.

Yet exactly what constitutes an "assault weapon" is a contentious issue and something that riles up some gun advocates. In fact, many of the large gun groups consider "assault weapon" a made up and ambiguous term invented by the anti-gun lobby in the 1980s, maintaining that guns don't actually "assault" people.

That said, the gun industry's traditional definition of an "assault rifle" is a weapon the military generally uses and has "select fire capabilities," or the capability to switch between semi-automatic or a fully automatic mode. However, the civilian AR-15s do not have the select fire capabilities, only semi-automatic settings, so the firearms industry insists they are not an actual assault rifle or assault weapon.

To be clear, though, the federal government usually refers to a military-style weapon capable of firing multiple rounds, either semi-automatic or a fully automatic firearm.

Regardless, the controversy over the AR-15-style rifle stems from its widespread use in some of the nation's worst mass shootings.

The AR-15 weapon used by accused shooter Nikolas Cruz at a high school in Parkland, Florida, is a semi-automatic version of the U.S. military's M-16 rifle and was included in a ten-year ban signed into law by President Bill Clinton in 1994. That law also banned the semi-automatic weapons used in other mass shootings, including the Oct. 1 massacre in Las Vegas and the 2012 shooting in Newtown, Connecticut.

The National Shooting Sports Foundation, the firearms industry trade association, points out on its website that the "AR" actually doesn't stand for assault rifle or automatic rifle but dates back to the 1950s and refers to the company that developed the weapon system, Armalite Rifle .

"AR-15-style rifles are NOT 'assault weapons' or 'assault rifles,' according to NSSF's website . "An assault rifle is fully automatic — a machine gun. Automatic firearms have been severely restricted from civilian ownership since 1934."