-If you aren't willing to fight, don't bother
-If you have 5 determined attackers and they are armed, you really don't stand a chance unless you can use tactics to overcome their numerical superiority.
-If you can't hit what you are shooting at, it won't matter how many round you have
-You have to have a weapon that you can use effectively
Honestly, chances are, if you just draw a weapon, a lot of criminals will just take off at a run, those that don't will probably run if you shoot one of them.
Those that don't do either of the above, will likely kill you no matter how many rounds you have because they have the Mindset that they are going to get YOU no matter the cost to them.
That type of Mindset is difficult to beat with Close Air Support.