Comment: Most people would assume that Clinton was not speaking in a technical way about semi-automatic weapons when she used the term 'weapon of war.' Semi-automatic weapons may not be used in warfare today but weapons like the AR-15 and more specifically high-capacity magazines constitute war-like weapons that mass murderers and terrorists have used to create war-like slaughters in areas frequented by civilians in the U.S.  
While the distinction between the weapons for some firearm connoisseurs might be vitally important  (a semiautomatic weapon fires one shot every time the trigger is pulled while an automatic weapon fires continually until the trigger is released) it is likely less compelling to the non-connoisseur who cannot but observe obvious 'war-like' conditions occurring in civilian spaces in the US. Greater regulation of high-capacity magazines, ammunition and firearms such as seen in other firearm-owning nations, seems inevitable in the long-run.