I've loaded the .17 Fireball a lot, and shot it a lot on prairie dogs. A bunch of powders work very well, including the 4198's and Benchmark, but my favorite is TAC, which is not only fast and accurate but flowed more easily through the little neck than extruded powders.
The round doesn't have as much range as the .204, but kicks significantly less, allowing an even better look at what's happening through the scope. And it has enough range to hit PD's as far as most people can hit them. My longest kill with the round was around 620, but it's best at ranges out to 400.
I generally prefer 20-grain plastic-tips for most shooting, but 25's hold up a little better in the wind.
