Phil:
The accolades for the .400 posted here are well justified IMHO. As a long-time user of the Jeffery .400 cartridge, I concur whole-heartedly. To get the best out of the cartridge, though, use only premium bullets. For me, this means bonded-core softs, and steel-jacketed solids (Woodleighs of course!). I expect the cartridge is adequate for elephant ONLY with good steel-jacketed solids.

I won't get into the mololithic-solid argument here, but most reloaders for pommie guns stay away from them, whereas most Searcy/Kreigoff/Merkel/etc users seem to get away with it ok.

The .400 Nitro is a GREAT double-rifle chambering when the correct bullets are used.