yep. most definately an HK-21
I'm gonna stop you right there, you just said an AR-15 is a high-powered rifle. It is obvious you don't know anything about guns and I shall ignore anything you say from this point on.
Just think if someone took a week or two to teach those guys how to shoot and properly maintain their weapon, they might actually achieve what they want...
"To disarm the people is the most effectual way to enslave them." -George Mason ΜΟΛΩΝ ΛΑΒΕ!