To most anyone who has ever served in the military, particularly in an Infantry related role, as well as many Law Enforcement Officers, an "Assault Rifle" would refer mostly to a military rifle, capable of firing in a full-auto mode. That is, a single pull of the trigger will fire all the ammo in a magazine or belt, until the trigger is released, or the magazine or belt is empty.
In the civilian market today, as it has for the past few decades, civilians have been able to buy similar looking civilian versions of those military rifles. But they fire in a semi-auto mode only. That is, they can only fire one bullet at a time, with each pull of the trigger. While some can be modified to fire full-auto, it is VERY illegal to do so, and even then, it takes more than a novice to do so.
WHY would civilians even want a military "looking" weapon? Well, for me, I love the added features of them. The military weapons endure weather conditions far better than a typical "hunting" rifle. The pistol grip, while Nancy Pelosi wants them banned, provides for better control. And, I simply like having the same type weapon platform that I used when I served in the ARMY. Oh ... and the availability of add-on accessories is far better than average weapons!
A hunting rifle will most often have a bright/dark blue metal finish, and most often be bedded in a nice walnut (or other hardwood) stock. Both those features, while very enjoyable to look at and hold, are very susceptible to the outdoor elements that would cause rust and damage to the wood. I own a couple of these also, and one in particular is a real beauty.
Another feature, is AMMO. While the military is required (under the international rules of war - the Geneva Convention) to use only full-metal jacketed bullets. Civilians can use the same ammo for many sporting/competitive uses, and the military ammo is often cheaper because it is so widely available all over the country. So having a firearm that shoots the same ammo as a military weapon, opens the availability of ammo to purchase, often cheaper than non-military (or NATO) ammo.
But back to the so-called "Assault Weapon" - Most non-shooters don't know the difference between such referenced firearm, and a commonly available firearm of similar abilities and operation.
I am providing a photo of two such rifles to compare. One is an AR-15 type rifle, which is a copy of the military M-16. The other is a Ruger Mini-14 Ranch Rifle. Take a look at the photos, read the descriptions of each, then tell me - Which is more deadly? Then tell me, what would banning the AR-15 really accomplish?
Lastly, an every day available rifle, that in my opinion is far deadly than either of the above, would be a common deer rifle, like this Remington 700 bolt-action rifle. This type rifle fires any one of the many types of hunting bullets, all of which would easily pass through a bullet-proof vest, car door, windshield, house door, wall, etc. A skilled deer or varmint hunter, can fire this type rifle with a great degree of accuracy for hundreds of yards, well out of range of many police holstered weapons. (BTW - The average Police Officer practices shooting far less than the average hunter!)
Lastly, while the magazine capacity argument goes on, I wrote an earlier post about such matters. See http://american1st.blogspot.com/2012/08/tic-toc-tic-toc-tic-toc.html I proved that a man with multiple magazines of 7 rounds each, can cause a LOT of damage IN A SHORT TIME!