"I gave you a site with a different perspective, please read it through."
And one whose reliability is questionable.
Do you really believe that something like the PGU-14 (the DU round) which is essentially an APCR, with all the disadvantages that this configuration entails and is by now decades old in design, has such magic penetration capabilities to enable it to rip apart tanks at 6000 meters?
There are cutout pictures of it all over the web.
http://www.airforceworld.com/attacker/gfx/pgu14b.jpg
Its official penetration data may still be classified but it is definitively not some top secret magic uber round capable of unbelievable performance.