RE: Best arrow for elk
the one that flies best out of your bow
don't worry about KE, speed, weight etc etc, Connie Renfro shoots elk, sheep, goats etc with a low 50's poundage recurve probably arrows going no more than 160 fps and KE of I'm guessing upper 30's ?
just hit the elk in the lungs, using a compound doing that with an old Pucketts Bloodtrailer will get your tag filled !