Fella's;
I owned a 591, sweated blood to buy it. That was when I was literally a poor, near-as-dammit-starving, college student. Only a year or so later, Remington quit making the guns & not too long after that, ceased production of the ammo too. I have never forgiven Remington for that.
I have never heard of any more 5mm magnum ammo being made beyond the original Remington production run. I sincerely doubt any more will ever be made.
I loved that gun, and the way it performed. But, seeing the writing on the wall (Hell, it was hard to miss, being in flames 10 feet tall!) I sold it & made money doing so. I've always felt that if Remington had marketed the concept correctly, the .17HMR would not exist today.
I've not purchased a .17HMR either, once bitten & all that. Frankly, with the guns I now have, any of the sub-.22's answer a question I've never asked. The 5mm will always have a collector's value though.
900F