a 17 fireball is the old 221 fireball, necked down to 17. It was originated about 50 years ago , by a wildcatter, who was pretty famous , I don't remember his name now. It was then called the 17mIV, or 17mach4. It will do 4000 fps with a 25 grain bullet, and it uses of course a small case, with very little powder. the 17 remmy is famous for fouling bbls, but not the m4. I have a friend who has a m4 rifle, and has been shooting it , for about 40 years now, he says it is absolutely the best varmint getter he has ever shot; 22 mag recoil, with a straight line laser shot out to 300 yds. If I reloaded, this would be my round of choice; very inexpensive to reload. lots of 20 and 25 grain bullets, lots of cases to be had.
http://www.saubier.com/smallcaliber/which17.html
http://www.chuckhawks.com/17Fireball.htm
this data is a bit old, and not handloading type, but safe 'remington' figures.
If you handloaded , you should be able to get the 25 grain pill to do 4000.
plus there is a new powder out, made almost specifically for tiny bullets; I think it is
called reloader 17, and it is hotter and faster than the origional powder.