Hmmmmmmmm , I have handled a few SPS's in the new fireball round but havent seen any ammo for it yet...go figure!
I see it as a great marketing ploy by Remington,the 221F, ,while a good cartridge itis dead, since they have the tooling set up for the brass and probably have a ton of brass on hand someone there came up with necking the it down thus reviving the 17 machIV...changing it litte and calling it the best little 17 to come out since sliced bread.

What is old is new again! just my $.02