Hate to break it to G&M readers and the author of this screed, but I have thousands of rounds of ammunition in various calibers. I know guys who shoot 20000 rounds a year.
The only difference between me and the Vegas shooter is that I'm not batshyt crazy, and I wouldn't be batshyt crazy if I had access to the same types of full-auto firearms as he did. 
A gun is a gun is a gun.