I live in elk country and I shoot 100 grain.
That's an age old question, about more weight and penetration. You add weight and I suppose it should penetrate more, but it also slows down the projectile. At what point does the added weight cancel out the penetration?
I'd say stay with what you and your bow are used to, and don't worry about it. I'd concentrsate more on getting in shape, practicing, and good shot placement.