I actually think it is probably fake government propaganda. It appears to be a 9mm round with a funny shaped bullet. Even if the bullet had a depleted uranium core it would still not have enough energy to penetrate 8mm of steel. The only way I can see it happening is either a small High explosive shaped charge in the bullet but you would likely need a larger bullet to make it effective, or an extremely hot loaded 9mm round with a super dense hard core like tungsten or DU and even then iffy. The super powered bullet theory is also unlikely seeing as this lightweight pistol recoils essentially the same as any other. Those holes in the steel appear to be of minimal displacement and around 5-6mm indicating they were likely inflicted by high velocity 5.45x39mm rounds and edited to appear like they were being fired from a pistol. A pointy bullet shape will help a low powered round like 9x18 or 9x19 penetrate soft fibrous woven armor like kevlar but when it comes to steel armor (harder than the bullet) velocity is what defeats it. Just shoot some sheet metal with a 5.56mm and a 9mm and observe the difference in the impact holes, the 9mm will leave a large dent with hole in the center, the high velocity 5.56mm will leave no dent whatsoever with a very crisp clean hole with a tiny amount of molten splash displacement right around the rim of the hole, almost as though it was drilled as was seen in the steel plate on the video.
If it is real it is just a 9mm with a tungsten/carbide or DU core firing into a very soft mild steel plate.