I always have to laugh at the "assault rifle" hysteria.
Like you point out, a lever action .30-30 is more powerful. And lighter and shorter than an AK-47. It must be that pistol grip on the "assault rifle" that makes it more dangerous.
>>> It is slightly less powerful than the .30-30 <<<
Slightly is the key word here. after 150 yd. The 7.62x39
starts Becomes more "powerful" that the 30-30