I was going to dissect the phrase "semiautomatic military-style assault weapon" but that's been done ad nauseam since 1994. Rather, let's dissect the argument itself.
According to the 2013 assault weapon legislation submitted by Dianne Feinstein assault weapons are:
"All semiautomatic rifles that can accept a detachable magazine and have at least one military feature: pistol grip; forward grip; folding, telescoping, or detachable stock; grenade launcher or rocket launcher; barrel shroud; or threaded barrel."These features make the rifle displayed below "military-style" but there's something crucial missing in the analysis. Of the military features listed, which one makes the rifle dangerous from a functional perspective? The grip and stock characteristics make the firearm easier to hold and adjustable for different situations. Not a single mass murder in the history of the United States has included the gunman launching grenades or rockets at their targets! Furthermore, why is a barrel shroud (the cylindrical part directly above the word "Bayonet" in the picture below) dangerous? It's sole purpose is to prevent the gunman from injuring themselves on a hot barrel.
Basically, these are features that make and AR-15 rifle look like its military counterpart. But looks and functionality are completely different things. There are multiple assault rifles (this term is a real one with distinct functional meaning and not meaningless the phrase "assault weapon") that are standard issue for the U.S. military. They are the M14, M16A4, M4 carbine, Heckler Koch HK416 (special forces), FN Herstal Special Operations Forces Combat Assault Rifle and the Mk 14 Enhanced Battle Rifle. They all have a similar function that the AR-15 and all the rifles in the 2013 assault weapon legislation don't have. SELECTIVE FIRE!
"A selective fire firearm has at least one semi–automatic and one automatic mode, which is activated by means of a selector which varies depending on the weapon's design. Some selective fire weapons utilize burst fire mechanisms to limit the maximum number of shots fired automatically in this mode. The most common limits are two or three rounds per trigger pull. Fully automatic fire refers to the ability for a rifle to fire continuously until the magazine is empty. "Burst-capable" fire refers to the ability of a rifle to fire a small yet fixed multiple number of rounds with one trigger pull. Semi-automatic refers to the ability to fire one round per trigger pull."Military personal don't use semiautomatic rifles in the field. They are inadequate for combat.
So, from a functional perspective the assault rifles they are trying to ban behave like your typical Chiappa White Rhino Revolver. Don't believe me? For comparison, here are videos of the worlds fastest shooter, Jerry Miculek, firing 6 rounds from a Chiappa White Rhino Revolver and an AR-15 Modern Sporting Rifle. Note that each firearm requires one trigger pull per round fired. There no dramatic difference in the time needed to get off six rounds, is there?
What else is a major component of the ban? Large capacity magazines, defined as a magazine that accepts more than 10 rounds. There is no coherent explanation for the 10 round limit. It is arbitrary and meaningless, as New York has already tried to reduced that from 10 to 7 rounds (they are backing off that because 7 round magazines don't exist.)
The claim is that banning high capacity magazines would reduce crime or prevent mass shootings. It's said that mass shooting culprits could have been stopped if they were required to change the magazine more often during their rampages. Besides being utterly false, the anti-gun lobby have physics against them. You see, the reason Gabrielle Giffords' shooter Jared Loughner was stopped wasn't the magazine switch. He was able to do that. The problem was after he switched the magazine, the handgun jammed!
This is a common problem with high capacity magazines because of a physical property called compressive strength. In short, the more you compress the springs in a firearm magazine, the closer that spring gets to its compressive stress value - where the material fails completely. More rounds equals a higher compressive stress value which leads to more firearm jams (Physics is a beautiful science!)
Ironically, this means that lower capacity magazines are less likely to jam. It's possible that the Virginia Tech shooter knew this because he packed his bag with 19 magazines that carried between 10 and 15 rounds each.
See the real problem here? The anti-gun lobby knows almost nothing about firearms. So their representatives in Congress invariably author legislation that is illogical, ineffective, superficial and counterintuitive. Having someone that knows little about firearms author firearm legislation is like having Gorgon Ramsay teach dancing classes.