The .357 Sig will be here a long, long time. Interchangability with .40 makes it a versatile pistol, and the figures on paper wow admin types.
Keep in mind the title of the thread: "
Next cartridge to become obsolete?"
I would have to agree that the Remington short magnums are going, if not gone, as they have even less popularity than the Winchester short magnums, which have questionable survivability.
The .32 NAA is still hard for me to classify as a production round, as it's only made by specialty makers like Corbon, and I still think of it as a wildcat. But it's definitely a contender.
Every once in awhile I think that the .257 Roberts is on its way out, but it's hanging on. (good.) Same goes for the 16ga. shotshell.
The .250 Savage is hanging on by the skin of its teeth, but that's mostly because of diehards. (Gawd bless 'em.)
The .38 S&W is a pretty sickly round, and is fired exclusively in old guns that are out of production, and which are usually every bit as big as thouse chambering more powerful rounds like the .38 Special.
The .38 Special has experienced a rather impressive comeback over the last 15 years, due to the huge selection of snubbies available for it. Good deal. Our grandkids will still know that old round.
The .41 Long Colt, however, is gone. Utterly gone. 3 years ago, I bought a box from Old Western Scrounger for over $50. These days, it'd run even higher, if you could find it. This round fell precisely because the .38 Special became some popular. With practically identical ballistics at the heavy end and more options and an inside-lubricated bullet on the .38 Special side, the .41 didn't have a chance.
I don't expect the .480 Ruger to last long. With the .454 Cassul still going strong and with the .50 S&W the big boy at the bicycle rack, the .480 Ruger really doesn't have the appeal of popularity or "biggest" to anyone anymore. Expect it to fade out.
The .300 Norma Mag (while a good round) really doesn't have much of a place, does it? Likewise the H&H? (shrug) But then, we've been betting on one to fall out for over 20 years, with nothing doing, and still more .30 mags entering the fray.
I frankly see no reason why, in a world with so much redundancy, we couldn't keep the GAP round. (Do I want one? Not really, no.
)
The .17 HMR is a cute rimfire that's not going away for a long time. I know too many guys that rave about it and shoot it by the caseload.
The .204 Ruger appeals to the "Faster Is Better" crowd, without offending them with recoil. Just yesterday at the range my 86-year-old great uncle was raving about it, and couldn't wait to show his off to me. It'll be around for awhile.
It's a fun game. Frankly, it's one of my favorite games in my hobby of firearms.
Isn't variety wonderful?