It is a great way to start messing about with Max type loads in the original chambering so you can warm up to the idea.
I would predict that H&R would have no problem selling a 357Max. chambered rifle (again) over the 357Mag if they would just do it.
After all, nobody anymore chambers a 22Short rimfire, they are 22LR and take Shorts and Longs too; same thing with the Max.
That said, mine is still in Mag as I have determined that what I want out of this rifle is sub-sonic load shooting and the Mag case has more than enough capacity for those velo's and it is accurate 'enough for me'.
If you want or need the capability of getting up into 35Remmy ballistics also, then the Mag wont do it. Long loaded it will get into low end Max data, which is pretty stout, be sure on that, but its not into Remmy territory.