Unless they are wearing Level III+ rifle plates, any 5.56mm, 5.45x39mm, 7.62.39mm will punch through armor. At close range, some will even go through Level III plates.
Even the hot 7.62x25mm Romanian Tokarev ammo will go through some rifle plates. It’s all about the speed coming out of the muzzle.
I had a batch of 7.62x39 that was steel core, it zipped through a ½” steel plate backstop angled towards us at 45° and boy, was my face red... OOPS!
I’m a long time 7.62x51 shooter,but you should see what some .22-250 loads penetrate under 100 yards.YouTube has some videos available.