You wouldn't have gained a lot from the .17 Fireball--but maybe not as much, since the .17 Hornet's a little quieter.
The bullet situation hasn't changed vastly, but there's a little more selection. Nosler getting into .17's with their Varmageddon line helped, but what would really be great (especially for larger varmints) is a .17 caliber Ballistic Tip or two. The heavy base helps them penetrate deeper, but all Ballistic Tips are boattails, and very few .17's are--which may be why there isn't a .17 Ballistic Tip!
Until relatively recently, powders were the problem with all the Hornet-based rounds. Basically, the powders that burned slowly enough to get higher velocity were too bulky to get enough in the case, and the smaller-granuled powders were too fast-burning. These days there's a wider range of suitable powders. I usually use Accurate 1680--which Hornady's manual lists as the powder getting the highest velocity with 20-grain bullets, 3750 fps from a 24" barrel. In the 22" barrel of my CZ, 12.0 grains of 1680 (.4 grain under the Hornady max) gets 3600 with the 20-grain V-Max and 3680 with the 20-grain Tipped Varmageddon. The V-Max groups a tiny bit better but the Varmageddon shoots a tiny bit flatter. In reality I can't tell the difference in the field, since they both shoot to exactly the same place at 100 yards.
But several other powders also work well. Both Accurate 2200 and LT-30 get around 3500 with 20's, and H4198 gets 3600. With 25's, Accurate 2200 gets 3100, and since the standard twist for the .17 Hornet is 1-9, it also stabilizes the 30-grain Berger. In my rifle H322 gets 2900 with the 30, and very fine accuracy. That might be the bullet for bigger varmints, but I mostly use my .17 Hornet for rodents.
