JabaliHunter,

The whole SD thing is a bit of "bollocks" if you excuse the French.

I fell for that trap and went with 535's, 570's and some 600 grain bullets on a buffalo hunt. I was in a position to shoot numerous animals and thought a great opportunity to try the different bullet weights.

With the 535 Solids I couldn't get any to stay inside a Buffalo. These were driven at 2360 fps out of my 22.5 inch barrel.
The softs folded a number of buff most emphatically and achieved over a meter of penetration. They expand to about an inch by the way. (These were Woodleigh RN and PP ). The PP's probably went 20% deeper.

The 570 grainers went another 10% (maybe) in penetration. Again Woodleigh's. These were doing 2280 fps. The 600 grainers were pushed to about the same speed as the 570's, penetrated about the same distance, but kicked and moved the rifle round lots more. ( Not sure they made any difference on the buff )

The Jeffery made it's reputation with the 535 grain bullet. Current users, like Tony Sanchez Arinho an Harold Wolf continue to use the 535 grainer on elephant and African buff. I used mine on Asian Water Buffalo, Scrub Bulls and large boar. It was absolutely emphatic and in no way could you suggest it lacks penetration with the 535 grain bullet.

Excuse the long diatribe, but I have done it with this cartridge and am keen to set the record straight.