First the term "weapon" is too broad as the only assault weapon is the assault rifle.
The German military introduced the assault rifle during WWII.
Since then an assault rifle has been defined as a short light military rifle (more or less carbine length) capable of selective fire, that is, two or three modes, semi-automatic, full automatic, and optionally burst mode, that fires a cartridge that is smaller and reduced in power compared to the standard infantry rifle load in order to keep recoil within manageble limits.
Now days the assault rifle has become the standard infantry weapon. The M16 is an assault rifle, note the 223 cartridge is smaller and lower in power than the 30-06. The AK47 is an assault rifle using the 7.62x39 cartridge, smaller than the 7.62x54R cartridge that preceded it.
Note that the so called "AK47" you constantly hear about in the news is invariably NOT an AK47 but rather an AK47 look like semi-auto only. (Cosmetics are everything in this game, ignore real substantial differences.)
Not also, that the term assault rifle, properly used, does not include handguns or submachine guns.
Note that on the network news and in anti-gun propaganda the so called "assault weapons" are invariably described as "high power" in spite of the fact that they use cartridges reduced in power from those used in standard rifles. This is a word game, facts need not apply.
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