There is a new thread on AH titled Bullet Performance Data Base (https://www.africahunting.com/threads/bullet-performance-database.37971/). Please post your experience with NPs on the Zebra and other animals providing you have "data" on them. I think a good number of AH reloaders would be interested in the failure you had.
I'll dig up the pics and try to post tonight. There was a typo in my post above. Retained weight of the lead piece was 77 grains, not 47.