200 Apples, nice pic of the 600 NE. I read your link and they show that same pic, labeling it as a 600 Nitro Express.
The cartridge in that pic ain't no 600 Nitro Express! It looks more like a 4 bore. I became suspicious when I say that lead bullet, 600s were never loaded with lead bullets. I was even more attracted to the size of the round compared to the size of the hand that is holding it. Perhaps the person is a dwarf, but the average thumb of the average hand is slightly larger than a 600 bullet. the thumb in the pic is nowhere as large as that lead bullet. An average index finger is about 3' long, the length of a 600 case. The case in that pic is at least 4' long, which is about average for a 4 bore.
Yes, I have fired 4 and 8 bore rifles. The 4 bore I fired had a 4' case, a 2000 gr bullet and a 385 grain powder charge. When I hear people talk about the "push" of the old black powder rounds, I just smile and turn away. "Savage" is more like it. The 4 bore cannot be fired from the bench, it will knock you off the chair.
Someday I intend to get a 458, just because I have always wanted an Elephant gun. For no good reason. And that is reason enough.