[Chemist_Geek]

Sources with the Bureau of Alcohol, Tobacco and firearms told News4 it is likely a Colt AR15, much like this M-16, or a Ruger Mini 14.

Does anyone know if these all use the same ammo?

Yes, in an out-of-the-box condition, all three would use .223 Remington, the American civilian loading equivalent to the 5.56mm NATO.

[ET(end tyranny)]

Could or would there be any reason for using more than one.

Are they comprable for distance?