I certainly knew re: the front on chest shot as it would be the one to take in my mind,i do know of bullets skipping off heads held flat ( .17`s on foxes at times etc) and i have read of the same on Cape Buff,but of course if he was coming at me i would be giving it to him up the nose as quick as possible a fairly good lead into the brain with that head up attitude.Funny things bullets i once shot a big sambar hind with my 308 norma the bullet slightly grazed her eyelid and mushroomed inside without leaving her head or leaving any other marks,as she was above me on a very steep hillside she then cartwheeled down the hill at an incredible rate all the time her head contents were whipped out with force through her throat leaving her with only an empty headskin--funny things bullets can do at times.Most nasal passages lead up into the brain even at the wrong angle at times and can be a great aiming point for sure.Broad side brain shots are of course possible by your pics---if he aint got a horn on that side lol.