The main rifles I've seen depicted in this conflict are AK pattern rifles, with the rare ancient armalite pattern rifle scattered among them, and a singular SCAR.

Based on where most modern AK manufacturing has moved to (China, like manufacturing writ large), you should instead be asking the Chinese populous to protest. That said, I wouldn't hold my breath on China forming a mass protest culture any time soon, Tiananmen Square is in most people's living memory.

> Those are US weapons that are used to kill!

I think it's important to raise awareness, and do whatever we can to oppose this sort of activity, but what is your source for this claim specifically?

I have been unable to find any substantiating information that US is supplying weapons, or aide of any kind, to the Rapid Support Forces of Sudan.