Blast damage from supersonic (or faster) wave of water coming in will mishape/misform/compress all forms of steel. A SABOT round from a 120mm tank is slower velocity than 6000psi+ velocity of incompressible water. Perfectly compressed miniature? No. Piece of metal that won't fit on anyone's finger? Yes.
No, it is not. A tank gun has a chamber pressure of 73,950 psi. Metal objects are not compressed very much at all, though they will be reshaped.