Riffraff,
I see where you're coming from. It'd be a sad day to either have to use all 7 rounds, or having to need more than 7 (multiple attackers). If you miss 7 times and it's likely there will be a few misses , then the shooter had better be concerned as to where those misses are going.
No disagreement, I was wondering from a legal standpoint.
Now, that said, there have been gangs attack folk in bigger cities, and then...well, one had better have a lot more than 7 rounds - an AR, a fast car, and 911.