Now an APC we can buy, we can even buy tanks and artillery but all the weapons have to be demilitarized (made unusable).

I have owned many guns in my life and none of them have ever killed anyone on their own. They have set on my end table or in my holster and none have ever gone off on their own. The guns aren't the issue it is the person holding it. There are some who just want to take guns away from everyone and will use any excuse to try and do that. Some people would rather do that than try and fix the bigger issues involved because the guns seem easier than trying to defeat terrorism or deal with mental instability.