I guided a guy who used a 500 BPE on water buffalo here. The hunter did not wish to shoot unless we were within 30 yards and we got to 27 from memory. This particular animal took a few to put down so it is like any other rifle in that you need to do your part. Penetration seemed good enough to do the job though I cannot recall what load he used. The first shot damaged the animal badly and he pulled up fairly quickly where we finished him. I would say it can do the job but there is likely not a great margin of error. This hunter was very fussy about his loads and he tested extensively before he came out so I would say his loads were as good as they could be. We had to pass on a few animals that we could just not close in to 30 on so going by only this one experience you may need to be prepared to pass on a few till the right situation comes along. I can probably ask him for some load information if you like. This particular hunt was exactly like guiding a bowhunter. I was constantly ranging and looking for the perfect situation. This is just my experience in this one situation so take from it what you will.