Well basically Yes it is.
Manufacturers chambering it. 2 remington and cooper.
Factory ammo. Seasonal runs only, I havent seen 220 Swift ammo on the shelf since 2000. You can special order from Nosler for 86 bucks a 20 but Its OUT OF STOCK as is Remmy and Win. Norma doesnt make it any more.
Brass basically only 1 Norma, Remmy and winchester are pretty much dead. 8 years now and counting.
In the ammunition business, a cartridge is labeled "obsolescent" when new factory made rifles are no longer being produced for it, but factory loaded ammunition is still available from at least one of the major ammo companies. After the last factory loads have been discontinued the cartridge is usually referred to as "obsolete."So by definition if the Swift isnt obsolete, it might as well be.
Addendum : Model 16 (discontinued) - single shot action for cartridges based on the WSSM family, as well as 6BR and 6 mm PPC.
The 6ppc and all WSSM cartridges are gone. The 6BR is still chambered in the Model 22.