It is real.
But we need to clarify what the bullet is doing.
It is not spinning like it would immediately out of the barrel. In other words, that is not spin on an central internal axis induced by the rifling.
What is happening is this:
The bullet is hot. if it was also a carry piece, it would be a little warmer due to body heat AND the explosion.
The ice is cold(duh). The hot bullet is causing some of the ice to go from solid to gas(ice to steam, or water vapor, for you bad science guys).
As the surface of the bullet touches various areas of the ice that is in a larger shape around it, it turns ice into water vapor.
The expansion of that water vapor gives the bullet a little push.
The bullet rests somewhere else and the cycle continues until the heat energy has been dissipated.
A simlar experiment would be to get a large piece of ice and drop a hot penny on it. When the ice is cold enough and the penny is hot enough, you can make it "dance" and squeak before it cools down and/or melts into the ice.