Because most of these killers aren't trying to kill as many people as possible. They're trying to get attention and "revenge" on society. I'm convinced Columbine literally started this whole thing, due to the way society views it.

>The fact that this 18 year old kid was able to order so much ammunition online is so ridiculous

Sure... but I still don't believe this 18 year old kid would have just given up on his plan to seek revenge. What would stop him from ordering or acquiring a machete and doing essentially the same thing?

There was a knife attack in Japan that left and equal amount of people dead. https://www.cnn.com/2016/07/25/world/japan-knife-attack-deat...

I honestly believe that tighter gun laws would reduce gun deaths... but I think its disingenuous to suggest they would prevent these mass killings or even meaningfully reduce the amount of deaths. Shown in my other comment, other and arguably even easier methods have proven to kill more people.