I feel somewhat bad for you, I have a wonderful life and nothing consumes any one part. I am however broadly knowledgeable or will strive to be on the subject before opening my mouth. I see well trained experts on the news day in and day out, I'm not impressed and find it sad we can't have better than that. Here's an exercise for you; why did the US army go to a short barrel , 12-14" for use in urban combat? Why do you think the Israeli's use  use Uzi's? Hint, close quarters!