I have a month, a place to avoid retaliation, the target can't run away or effectively hide, and no creature in its entire evolutionary history has ever seen a ranged attack before. Each time I hit it, it weakens snd slows as it bleeds, expends energy, and fights infection.

I like my odds with the sleepytime atlatl poo-spear better than being 1 of 20 guys trying to peel a mammoth off from a herd in random terrain.