Back in the day, when I worked at the gun shoppe in Georgia, we came up with an idea to explain various hollowpoint rounds to customers. At my boss's house, we filled a big ol' plastic chemical drum with water and fired down into it from his deck using various calibers and brands of ammunition. At the end of a session, you would dump out the water and recover your now-expanded bullets from the bottom of the barrel.
No handgun bullet we were using (not even IMI/Samson .50AE JHP from the notorious Deagle) would damage the bottom of the barrel after traversing more than three feet of H2O. A 240gr HydraShok fired from a 16" Marlin .44 Magnum carbine, on the other hand, displaced a good deal of water some fifteen feet vertically, tipped the barrel over from the resultant sloshing, and did, in fact, nick the bottom after shedding its jacket and the "petals" of lead from the hollowpoint cavity.
The "blossomed" hollowpoints were very popular conversation pieces on the counter at the store, and tended to grow legs and wander off, especially the highly photogenic (and very pointy) Winchester "Black Talons". To my knowledge, however, none wound up being used in such a clever and artistic fashion.
(Via Greg via Unc.)