The best hunter I have ever known could pretty much kill deer on command and did it with an old Auto 5 12ga. shooting whatever rifled slugs were on sale. His "upgrade" was a homemade peep sight which consisted of a lollipop of sheet metal with a hole drilled in it, bent and taped to the receiver with a little wood wedge to get the elevation just right. He sighted it in on cow patties.

Fear the Indian, not the arrow.

Bore size is no substitute for shot placement and
Power is no substitute for bullet performance. 458WIN