Haha, the old assault weapons debate. Banning them does nothing for the gun control crowd, for reasons gun control people don't understand or they wouldn't be making it an issue, nor are civilian assault weapons particularly well-suited for home defense, either, for the same reasons:
Assault rifles were designed for combat. Their improved lethality over battle rifles comes from their improved rate of fire. They sacrifice stopping power to attain it.
SMG's go even further down that design path so as to provide faster reaction in close quarters.
Automatic weapons are illegal for civilians in the United States (with rare exceptions*). Any talk of an "assault weapons ban" is a ban on weapons with full-auto capability already removed. Bush's "lifting the assault weapons ban" meant allowing the sale of the weapons in their semi-automatic form, NOT allowing the sale of automatic weapons. Those have been banned for over half a century and that isn't going to change.
In its civilian configuration the assault rifle is actually at a disadvantage compared to hunting rifles, battle rifles, and even shotguns and .45 caliber pistols because the assault rifle was optimized for rate of fire, not stopping power. If automatic weapons are illegal your most effective option is stopping power, so your best weapon for self-defense is NOT an assault rifle.
Hunting rifles, battle rifles, and sniper rifles are almost interchangeable. They all have the same types of very powerful ammo, long barrel lengths, and options for sights. They all have exceptional stopping power, can penetrate body armor, are extremely accurate, and have extremely long range. They're also ungainly, so they're almost never used in crimes, but when they are ("crazy guy on the clock tower") the results are truly awful.
The weapon most often used in crime is the Lorcin L-25 semiautomatic pistol. It's inaccurate, poorly-made, and its stopping power is pathetic. Criminals like it because it's cheap.
* There's a very rare and expensive license for legal possession of an automatic weapon. Some vintage collector's items, like the water-cooled machine guns from WWI or hand-cranked Gatlings, don't require the automatic weapons license. IANAL so don't go buying a Vickers Gun without checking the laws yourself first.