We've obviously heard a lot about these weapons in context to performance in flesh ad nauseum. Please don't do that here in this thread.
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We already know that HK's 4.6x30 MP7 round and FN's 5.7x28 P90 and Five-Seven round are generally only capable of penetrating soft armor....most rifle rated hard armor it's challenged against in open-source tests using US-sourced armor is a no-go.
So, what about these rounds versus Russian armor? Common wisdom suggests no, hints by industry professionals under NDA suggest no, but that Russkie stuff is hard to get your hands on....so wouldn't it be cool to see how it performs against a few different Russian armor sets from the era of its inception?
Here's a fun video: