I have a heavy target rifle chambered in 284 win, barrel length is 27 3/4". I use Lapua 6.5X284 brass necked up, with 180 Lapua Scenars, CCI BR2 and H4831SC. Currently running a mild load running at 2780fps with 12 fps ES, I also crimp my loads as I find this helps with ES. This rifle hammers the metal gongs very hard, and I would not hesitate to load up a 160 Nosler AB or Partition and use it for moose, or even some 154 GMX or IB, they would do the trick as well.
I am getting extremely good accuracy from this rifle, in the .2s and .3s when I don't miss the wind calls, but then I find the wind does very little to this combination out to 500 meters, thats when I have to pay real close attention!
Good luck with your new shooting iron, looks awesome with the Parker Hale action!