IvW, what do you think of the comments above re: .500NE?
I think it should be taken with a whole lot of salt.
I never heard of a 500 NE with a 18" set of barrels. So maybe they had one of these(that was cut down to 18") and yes then the performance as well as regulation would go for a ball of s....
They may well have tried it out and with 18" barrels and probably some ancient Kynoch ammo lying around and yes sure in that case it will not perform on big bulls in the thick jesse. To then generalise and say a 500 NE experiences penetration issues is ridiculous.
There may have been a few doubles around in the game departments but I can assure you that 18" 500 NE doubles where not standard issue to game department personnel. Tsuro, Richard Harlands tracker carried and used a 450 NE game department double that had it's stock butchered.
We need to bear in mind that these old time hunters who culled thousands of elephant used what they had available and what they were issued. A double makes a poor culling rifle when you are dealing with elephant herds and need to drop the whole herd in the shortest possible time.
A big double used by a professional hunter guiding clients and often hunting them in thick bush makes a whole lot of sense and may just be the best tool for the job.
The 500 NE in normal barrel lengths 24-26" loaded with a proper solid of 570 gr is devastatingly effective on elephant. It outperforms all other NE calibers up to and including the 470 NE in the penetration/knockdown department. (Not that any of the other doubles are not suitable).
Furthermore when compared to the .577, 600, 700 class well they just recoil too much and your recovery time for the second shot takes too long and they are heavy to carry all day. Some penetration tests I have seen shows that the 500 NE out penetrates these three big boys as well.
If I ever switch to a double it will be to a 500 NE for the big stuff and a 450/400 for the cat's, until such time I will stick to my 500 Jeff for the big stuff and my 9.3x74R/12ga combo and 12ga/12ga 24 inch barreled sxs(aka "poormans double") with brenneke slugs for leopard.