From a 2004 article...
"Military-style semi-automatic firearms (so-called assault weapons) do not differ materially from non-military style semi-automatic firearms (one bullet is fired for each pull of the trigger) and are no more powerful than other semi-automatic weapons. Further, a bullet fired from a semi-automatic weapon is no more powerful than one of the same caliber fired from a corresponding non-semi-automatic handgun, rifle, or shotgun. In fact most assault weapons are less powerful than hunting rifles. For example, the AR-15 which is a semi-automatic version of the military's rifle (M-16), is a .223 caliber rifle. Rifles of this caliber are often forbidden from being used to hunt deer because this small caliber bullet is more likely to wound the animal (and allow it to escape and suffer a slow death) than the more powerful .24 to .30 caliber bullets normally used in deer hunting rifles. (An example of rifle caliber restrictions are Tennessee deer hunting regulations. Click on "regulations" in the frame area.)
Assault weapons are not the weapons of choice among drug dealers, gang members or criminals in general. Assault weapons are used in about one-fifth of one percent (.20%) of all violent crimes and about one percent in gun crimes. It is estimated that from one to seven percent of all homicides are committed with assault weapons (rifles of any type are involved in three to four percent of all homicides). However a higher percentage are used in police homicides, roughly ten percent. (There has been no consistent trend in this rate from 1978 through 1996.) Between 1992 and 1996 less than 4% of mass murders, committed with guns, involved assault weapons. (Our deadliest mass murders have either involved arson or bombs.)
There are close to 4 million assault weapons in the U.S., which amounts to roughly 1.7% of the total gun stock. "
The term "Assault Weapon" was derived from California Leftist Politician David A. Roberti who along with his crone Mike Roos drafted legislation to ban military looking weapons because of a school shooting in Stockton CA. by a Racist Fascist wacko. Although people were killed in this tragedy, the media jumped on this to demonize "Assault Rifles" like the SKS, AK-47 and AR-15 sold on civilian markets. Below is an article written by a doctor who provides great information on how these political opportunist capitalized in this event...
http://www.cs.cmu.edu/afs/cs/usr/wbardwel/public/nfalist/fl_aw_report2.txt
Roberti-Roos started this campaign and knew little about firearms but they, along with the Liberal Media and other left-wing politicians in the California Legislature coined the phrase "Assault Weapon"
http://reason.com/9511/GUNSfeat.shtml
As their momentum continued they attempted to demonize these firearms and any one who might own one. Their campaign grew into legislation which eventually became law based on lies, half-truths and ignorance. In fact they were their own worse enemy as because of this ban, it induced many to join the NRA and acquire firearms that function the same as those banned, but were not part of the original law. It also created a swing to the right which eventually led to terms limits and other laws that would weaken the democrat influence in the California State Legislature.
There were attempts to unseat Roberti but eventually term limits ended his political career.....