Well check out tanknet for such reasonings. Theres been some discussion about it. However I donīt remember the exact thread, but have a strong recollection that DU does not benefit from hyper-velocities above some limit of maybe 1700m/s - 2000m/s.
Try this one:
http://63.99.108.76/forums/index.php?showtopic=18511
The problem with MarkSheppards thing of just increasing the velocity of M829A3 by 30% means that itīll travel somewhere over 2000m/s that is a problem, what Iīve read from the tanknet. However, if they chance the round to a heavier one with less velocity, is OK reasoning.
And I know that everything on internet is not true. But lets face it where do you have better conversation of such things than tanknet. Thereīs got to be a point somewhere, if everybody seems to agree..?