Director S. Craig Zahler has received a reputation for his unflinching portrayals of gruesome violence, but perhaps none of his cinematic moments matched quite the same levels of disturbing brutality as the infamous scene from his debut feature, Bone Tomahawk. The horror-Western is a slow-moving but suspenseful narrative that follows a vengeful posse as they hunt for a clan of cannibalistic cave-dwellers that terrorizes their small town. Zahler holds back from showing any extreme gore for the majority of the film, but his restraint pays off in the explosively bloody Bone Tomahawk death scene towards the climax.
https://screenrant.com/bone-tomahawk-gruesome-death-scene-explained-reason/