Rather than asking those of us that prefer to 404 a more relevant question would be to riflemakers: Why don't you chamber a rifle for 404J as a standard chambering? Winchester took a chance about 60 years ago on the 458 Win Mag and they sold all over projected sales. the same could happen with the 404J. Here's why: It can handle .423" bullet weights from 300 to 500 grains at velocity levels from 2100 to 2800 fps. It has performance on dangerous game while still having manageable recoil. It is suitable for all around use. It has a slightly bottlenecked cartridge so it doesn't need a belt for headspacing. The neck is quite long so even heavy for caliber bullets may be seated deeply and still not interfere with powder space. The cartridge base is "non-normal", being neither the .532" of belted magnums nor the larger diameter of the Rigby & Weatherby groups, but there are sufficient makers that finding brass is not a problem. Same thing for hunting grade bullets- great bullets are available from Woodleigh, NorthFork, Swift and others. the only freal downside is that there isn't much available for lightly constructed inexpensive bullets that a shooter could use for expanded range time. but that is a minor problem since there are cast bullets either available for purchase or cast by the shooter. At present I get .427" bullets from Oregon Trail. these are 200 grain bullets designed for the .44/40, but by running them through a .423" sizing die, they work well as practice/plinking loads. A near casefull of Trail Boss and these bullets allows for inexpensive range time, then finishing off the trip with bullets that duplicate the trajectory of the premium hunting bullets and the rifle becomes very well known to the user.
I really have two favorites when considering a boltaction heavy game rifle: the 404J and the 458 Win Mag. They are quite similar though having slightly different niches; but they both accomplish the same duty: sending a heavy sturdy bullet at sufficient velocity to put down any animal on Earth while not have retina detaching recoil, but also can be loaded with lighter bullets and loads for use on less dangerous animals and even those where rifles such as the 270 Win might be considered appropriate, but for the terrain that limits shots to less than 150 yards.
the more that I think about it, the more I am confused as to why no major rifle maker offers the 404J as a standard chambering.