What do you guys think?

As for the "skiing" of the bullet; I suspect that at the angle you were shooting at, the water acts like a solid object to the mass of the bullet at first, then gives way as its mass continues its downward pressure on the water. That's where the skiing comes from as the initial "hit" from the bullet and water redefines its trajectory to a plane in line with the waters surface at zero degrees. Then enough force is absorbed by the water until the conical nose of the bullet "re-grabs" the surface of the water and it gets redirected upward and out of the plane of water.

There is so much going on here it would take another video to break it all down. For instance, in your first shot with the .223 (but third bullet shot), the water in the background seemed to turn into vapor and disappear into the air. Something very interesting is going on there.