That won't reliably kill a bull.The correct spot to shoot on cattle is 1 inch above an imaginary line drawn from eye to eye, and centered. I've killed cattle this way, and my son does it for a living. As Gordon said, .22 Mag. is the preferred caliber.
Medula oblongata.
The way I was taught was to draw a cross from opposite ear to eye (left ear, right eye, ie) and aim through it for the spine. Normally culling big animals I'll be standing on the rails in the yards so a quartering-on shot through the eye will absolutely end up in the right place.
Pigs and goats mentioned, out to 50 yards. Any more and I'd get a bigger gun.