Until you see the work that heavy, fat bullets at moderate speed can do, maybe it is best not to comment on how well and how far they work.
In a carbine, it is fairly easy to get a 300gr cast WFN to 1500fps. When you run the charts, and look at the fact that a MPBR shot is roughly 150 yds, and that at 200 you are still on hair on an elk, it is hard to justify, at least in my mind, limiting shots to such short ranges. YMMV, but the numbers won't.
