2 things in the Rigby's favour:

The largest elephant ever shot was downed by a purpose built .416 Rigby that the hunter had especially made up for the job. Unless you find a bigger elephant or a tyrannosaur, it should do the job.

Second, Commander Blunt used the .416 Rigby to shoot over 1,000 elephant and is one of the few people in the 1,000+ club. I've never shot one, but in the circumstances I'll take his word for it that it is the ideal calibre. One of the advantages he quotes for it is that it is flat shooting for longer shots, compared to larger calibre rifles. So I'd think that any zebra or antelope at 250 yards is in big trouble.

I owned and used a .416 Rigby in a Ruger Magnum bolt-action. A good rifle, but I sold it with a view to replacing it with a Heym one day. Amongst other things, the Heym has a much bigger magazine.

One idea I had to ensure that Woodleigh solids did not get mixed up with soft nosed bullets in the heat of the moment was to use brass cases for one and nickeled cases for the other - and stick to it.

I had a platinum line put in the Ruger sights, (silver can tarnish). Also, I had the front sight replaced with a larger one. Elephant ivory can tarnish too and so a sight made from wart-hog tusk ivory would be better provided it was well glued in place. I also fitted a wider sling for the heavy rifle and quick detach swivels. The Swarovski scope with 30mm tube (which matched the .416 rifle bulk), had generous eye-relief and a spring loaded ocular cap which I considered good features on this rifle. Warne QD mounts never gave any problems and looked good too.