If you're going to make an argument, I'd suggest you to know enough to be accurate. Military weapons are not legal without special federal permits and licenses. I don't believe any mass shooting done in the last few years were done with "military weapons". And your term "high power" has no definition. One of the popular deer rifles is a WWII sniper rifle, the .308. Is that high powered? No rifle is a weapon of "mass destruction". That is reserved for nuclear, biological, and explosive devices normally. Not firearms that fire only one bullet for each time you pull the trigger.
I respect the first amendment as well the second (an all the rest), but I choose to understand what those rights mean and the responsibilities they put on me.