That was the 90mm caliber A&BP* AK-47 sabot round, with a depleted uranium tip for those REALLY tough brick walls.
The 30 round clips are really, really heavy...
*Armor & Brick Piercing
25 posted on 02/22/2008 1:11:43 PM PST by an amused spectator
(AGW: If you drag a hundred dollar bill through a research lab, you never know what you'll find)