Paul, can you assist in giving us results of this comparison??
Gert,
If the standard rifling twist stabilizes the very heavy for caliber bullet in this instance, the 470 grains that you mention, which in the 404 (.423) would have a sectional density of .38 (.37525 to be exact ) it still may suffer a bit in the speed department. I don't know what speeds can be achieved with it and if it leaves the optimum curve (stabilization/speed/energy/penetration etc...) at that weight. It may not.
It seems to me that the only way to measure it's efficiency would be on actual game shot at various distances. Since we know that a bullet that may seem stabilized on paper, may at times start tumbling immediately upon hitting a medium.
A very dense metal (sectional density wouldn't change) would provide a shorter bullet and therefore unquestionably enhance stabilization which is largely a function of length/shape of the projectile in a barrel. It may not be needed in the 404.
The larger bores may be more forgiving, I'm strictly talking in generalities. A full metal jacket over lead may be enough. I doubt however that a solid would stabilize properly.
To make up for rate of twist, speed is the answer but for approximately one inch more in twist rate, the speed needed is in the order of far more than can be achieved reasonably/safely in a cartridge. I know that in lighter bores an additional speed of 1000 fps to 1500 fps is needed (for bullets already going fast) to barely start compensating for the effect of lack of a faster twist and that that compensation is incremental at best...Too fast a twist has other adverse effects such as yielding slower speeds for example. Super high speed also has other effects such as creating a very elliptical trajectory at times very eccentric which would affect accuracy. In other words, in a long trajectory, which isn't the case for a medium bore, a bullet may over the course of its flight at various distances hit point of aim but also hit off of its point of aim at other intervals and distances during the same flight.
When Barnes still made a 250 grains bullet in .30 caliber, I bought a couple of boxes for hunting in a 300 Weatherby but never ended up trying them. (S.D of 250 grains .308 caliber is .37648 or .38) Very comparable to a 470 grains bullet in the 404). In fact almost identical which gives a good frame of reference.
After seeing in competition that from a 150 grains perfectly stabilized 7mm caliber going to a 162 grains bullet made all things go to hell; key holing on paper. (Speeds were under 2000 fps. for all bullet weights, these same bullets all worked well at higher rifle speeds, on average 1000 fps faster, in various 7 mm) To me the eye opener was that even though they were standard not heavy for caliber bullets, the slightly heavier ones suffered at low speed with barrels of slightly slower twist rates.
My examples may not apply to larger bores, since a 380 grains bullet in .375 caliber made in South Africa (S.D. .38603 or .39) from what I understand was working, a 470 grains in 404 may also work quite well. I'm sorry if I'm not providing concrete answers but these would be beyond my scope. The only way to know is to test. I personally like to experiment in an amateurish manner at the range but not while hunting when I stick to standard weight bullets, slightly on the heavy for caliber side.
best regards,
Paul
....peach and another shite flavour 
....wasnt even absolute mandarin.......
..... so on the 
Most of the clear drinking spirits made in NZ are a byproduct of Fonterra's dairy processing.
....not 
.........
gn bullet shot from a .458 Win Mag ...
Just poured myself a glass of Ardmore from the bottle I bought at Sydney airport, the other week! Mmm ... very nice! 
