It will depend on who is making the receiver.
Never deviate from published reloading data. You risk injury or death if you do.
The 475 Nitro is a low pressure cartridge. The 460 Weatherby is a high pressure cartridge. They use different powders. No, you cannot reload a 475 Nitro to 460 pressures because a gun chambered for 475 would not take the higher pressure.
There are several, such as the .600 Nitro Express and .700 Nitro Express, not to mention anything considered a cannon.
I think large, heavy, expensive, custom made double barreled rifle. To the best of my knowledge, there was one handgun made in .600 Nitro Express, more as a curiousity than a usable handgun.
Yes, here's several. .585 Nyati, .600 Nitro Express, .700 Nitro Express, 14.5x115... then you have weapons classed as cannons (20mm and up). The .50 BMG/12.7x99 isn't even remotely close to being the largest cartridge out there.
Rather than a sharp angle at shoulder and neck, Weatherby cartridges have a curve. This was done for a smoother flow of the gasses from the burning powder, and as you note, is a characteristic of the Weatherby cartridges.
Eldar Kai makes the powers of someone 10 times stronger than what they already are. Another way to express this would be to say they're tenfold times stronger than they originally were.
S&W .500 magnum. how about the 45/70 revolver ??? or the 600 Nitro Express
Way back when, rifles were made to use black powder. Newer technology came into being, with Smokeless Powder, which is based on Nitrocellulose (guncotton) and Nitroglycerin. These new guns had more power than the old black powder. To impress customers with the idea of the increased power, many cartridge makers incorporated the term Nitro and/or Express (a very fast train) into the name of their cartridges- like the Holland & Holland .600 Nitro Express. (Ummm- yes- new and improved- gotta go buy one. )
It can only safely accept the 270 Weatherby Magnum if that is what it is chambered for. If you want to chamber it in some other caliber than get a new rifle. Just because two bullets have the same diameter bullet (270 or any other caliber) does not make it safe to fire it in your gun.
is in the die design. Thoughts that flat area might help stop deflection.