My hunting partner and I have killed 68 with arrow weights between 420-450, and mostly from longbows and recurves between 53-57#. Now that I've had to switch to a compound, I'm shooting the same arrow package at 54#.
I shot 3 and 4 blade Muzzy 125s with a sharpened tip for decades, now shooting Iron Will 125s. Tuning and placement are the keys to killing elk, much more important than raw KE or momentum from a wobbly arrow.