The "shoot em up mentality" is not part of either ex-military or ex-cop makeup. I was a policeman for over forty years and only drew my gun once in all that time. At the RCMP Academy in Regina recruits were all excited when they knew they were going to their first firearms session. Imagine their disappointment when the firearms instructor said, "Im going to show you your most important weapon" and then he stuck out his tongue. So the firearm became a reserve item, not a 'shoot em up" priority.
People who are thoroughly trained in the use of firearms keep quiet about their skill because it is so deadly that they don't want to use it. It alarms me no end when someone announces that they are going to get a gun for personal protection yet never consider being trained in its use. One of the benefits of proper training is that you can also "read" the skill level and intentions of anyone who confronts you, so you do not necessarily become either a victim nor a shooter yourself. Take Don's sound advice; if you want to possess a firearm, take a course of instruction. You will feel safer, and more importantly, because you feel safer you act differently and the villains can read your body language, believe me.