It seems you are mainly interested in knowing about penetration. If so, you can build a Fackler Box and find out how well the rounds penetrate. You will not be able to see the wound profile, since you will be shooting plain water, but you will know about maximum penetration and hwo much the round fragments.
BTW, the round will penetrate about 1.8 times further in the Fackler Box than they would in calibrated ballistic gel, so adjust your figures accordingly.