I hate to beak it to you, but an AK-47 is not a high-powered rifle.
As rifles go, it’s sort of ‘fair to middlin’ on the power scale.
On top of that, there are very few AK-47s in the US. What we have are firearms that look like AK-47s. Semiautomatic look-alikes. Of course the news media always tries to blur the distinction. I don't think we should aid them.
It depends on what you are comparing it to, a 9mm carbine or a 22 are not going to penetrate body armor. But if you so ticky-tacky on terms what pray tell is it considered? I’ve never heard of a medium-powered rifle or low powered rifle. Perhaps I should have said most rifles.