[stash247]

ib969,you are a bit off topic, but let me offer this: The .17 Fireball is the legitamised version of the .17 Mach IV, a totally competent wildcat, for a lot of years; a lot more than either of the rimfire offerings.
As Remington's authoring of the .22-250, as a production number, so have they done, again, and God Bless them, with the .17 Fireball.
I am fascinated with the little .17's: the .17 Ackley Improved Hornet, and the .17 Bee, but may well buy a new Remington rifle, for the benefit of 'storebought' ammo, being available; we'll see about that.
I am, as well, working on a cartridge, based on the .357 Maximum, necked to .17, the rimmed equivalent of the fireball, with better case head strength, for use in single shot actions; again, time will tell.