.50 BMG tungsten frangible.
The Fragmenting High Velocity (FHVL) Round is a lead-free replacement that offers far superior tactical capability over the lead core bullet. The FHVL has the same range and accuracy as a lead bullet of similar weight. Long range, reduced ricochet, controlled penetration, and exceptional accuracy make the FHVL the most technically advanced tactical round available today. The FHVL grants the operator enhanced tactical capability, such as controlled penetration (NO EXIT) and increased ability to eliminate threats instantly, all while eliminating ricochet and over-penetration hazards.
That's some impressive technology.
They have movies! Don't tell PETA. They think ballistics gelatin has a soul.
H/T The Firearm Blog
The Phantom Gelatin Blaster.