I have not heard of any problems with x or y type projectiles in the 500 NE. All I can offer is the following picture of a Hornady 570 gr DGX that went through the pelvis and ended up against the diaphragm after traversing the paunch and intestines and liver. The effect was spectacular to say the least at 15 yards.

Final weight was 476 grs and diameter was 1.10"