Never shot a Buff yet but don't think I would shoot a charging Buff with a frontal chest shot with a 500 NE unless he was abit away--25yds ++.
If he rolling in fast and getting closer and closer I would think that the head CNS shot would be better shot to take--

Just supposing here, as there are many here with actual hunting experience.I will defer to their opinions.

How many out there would put 2 shots into the chest of a charging Buff with a 500 vs going for the head only with a 450/400?? Methinks a CNS shot on a closing Buff would be better, but what do I know?? Only what I have read.From what I read Buff tend to soak up lead like a sponge and keep on coming.

If I have a 450/400 I am definitely going for a CNS shot if charged!!!