Taylor's KO values are probably as good as anything around, which indicates the effect of a near miss.

You need the combination of sufficient bullet energy and penetration, to have the potential for "stopping." As Zimhunter stated, part of it is attitude of the enimal but only a charging animal needs stopping.

What works one day may not work the next, which is one reason for a backup hunter, whether a PH or someone else.

The 4000 ft-bs and 400 grs. is a courtesy to the 404 Jeffery and 450/400 crowds. It is not much of a stopper except in experienced hands. But then nothing is really a stopper unless used by an experienced hand, or turns out to be a lucky shot!