Not to make an issue of this, but my reference works list the Large Ring Mauser 98 action as accomodating a 1.100" barrel shank. I measured several take off barrels I have lying around the shop, and they all measured in the range of 27.9mm or 1.100". Earlier versions of the Mauser did indeed have one inch barrel shanks, as did the Krag and the Springfield.

I personally have a post 64 Model 70 barreled in .577 VSRE, the wildcat I have mentioned before, made from the .577 NE case shortened to 2.500" and turned to produce a rebated rim. The case is .660" at the base, which gave my gunsmith pause when he built it. However, he turned the barrel threads to maximum dimensions, giving the closest possible fit with the action threads, and I have never had a problem with it. Of course the pressures I use are quite mild.

According to my source, the German Research and Testing Institute for Hunting and Target Weapons, DEVA, the maximum pressure for the .404 is the same as that for the .303 British, 3650 BAR, so it should present no problem either.

From what I know about the Granite Mountain actions, they are tailored to specific cartridges and have dimensions which avoid the necessity of trying to shoe-horn a cartridge into an action for which it was not designed. Whether that feature is worth $2000 added to the final price is certainly up to the purchaser.