I'm sort of in the same boat using a 280 only I'm hunting nilgai - probably a slightly hardier animal than an elk. Anyway, I'm willing to sacrafice some accuracy just to get the penetration and bone-smashing effect. I'm not saying an 140 accubond won't do it, but I would select 160s over 140s...
My 13 year old son just drew a youth big game permit to hunt on the La Sal Vieja (East Lake) portion of the Lower Rio Grande NWR. You are allowed one buck, one doe and all the nilgai and feral hogs you can haul out. Oh man am I excited!!!!!!!!!! I went out this morning to scout the area a bit...