I doubt it makes a huge difference. I am sure Elk have been killed with arrows of all types and weights. I would however think the FMJ's tipped with a 125 grain Slick Trick Standard'swould be ideal. Any arrow weighing around 400 grains or above will work with your setup. I killed my 300+ 6 X 6 with a 390 grain arrow. Everyone told me it was too light but I got a complete pass through, and the Bull only went 60 yards
Have Fun!! Elk hunting is a blast!
Dan