If that situation happened to me (as it could have about 30 mins ago on my walk back from the pharmacy, as Honduras where I live is in the middle on a millitary coup) I would try and get a lead of the group. Beat them to high ground. I am 30 years old and in good physical condition but if I start losing my lead and being overtaken or feel like I am about to be flanked, flankers get it first. I practice action drills, walking and firing, strongside and weakside. I walk and shoot center mass as the threat continues putting me DIRECTLY in harms way. I continue firing as I make my way to choke point/high ground. Eventually they will get the picture, out of the 17 rounds in the Glock, I will make 13+ hits under preassure. This will get the point across UNLESS the mob gets your flank and then you are in for a very ugly, dragged behind truck and body left on display type death. I would not shoot round one until it was clear it was me or them and my life was in imminent danger. Even then I fould not just fire into the crowd. I would take out the fastest approaching threats, that would slow everyone else down considerably.