What’s the firepower like for the Army’s new rifle?

I was involved in an incident today. I didn't draw my weapon nor did I indicate I even had one. Before things got that far, the assailant realized his supporters were deserting him so he backed off. When you talk about restrictions what you need to be supporting is restricting those criminals who vandalize us, rob us and would end your life without a second thought.

I'm posting this with a simple question for the gun rightists here. Given the lethality of the AR15 and it's ascension to the gun of choice for mass shooters is there some level of lethality that should be with held from the public at large? At what point does the ability do destroy human life need to be restricted?