Since starting this thread I've done considerable more experimenting with the CZ .17 Hornet, both with loads and in the field. The cartridge has become my main long-range choice for "gophers" (here in Montana mostly Richardson's ground squirrels, but also in some areas Columbian ground squirrels) when the .17 HMR isn't quite enough to reach some of 'em. Partly this is because it's easy to drop 100+ rounds in a shirt pocket and go on a walkabout. This can also be done with my .22 Hornet and .22 K-Hornet, but they're not nearly as easy to hit with as the flatter-shooting .17 Hornet beyond .17 HMR range.
But the CZ has also become my primary prairie dog rifle. Not only is it easy to hit with out to 300 yards (which takes in 90% of PD shooting) but recoils even less than a .22 Hornet, so it's easy to spot my own shots, whether hits or misses. With 20-grain plastic-tips (Hornady V-Max's or Nosler Varmageddons) at 3600-3700 fps, it really does the job; in fact on one PD shoot this summer my hunting partners at first thought I was using a .223 or something similar, because of the way it flipped dogs.
Plus, brass has become very available and CHEAP since 2013. In fact I sometimes shoot factory ammo because I can't handload it any cheaper, and the resulting fired brass is even cheaper than I can buy component brass. And only around 12 grains of powder is required for all this performance.
Have also found the .17 Hornet performs to its potential with a wider variety of powders than the .22 Hornet. My primary powder is the spherical Accurate 1680, since it provides top velocities and superb accuracy with easy metering, but several other powders also do about as well.
H4198 is just as good as 1680 but more temperature-tolerant, though being an extruded powder it doesn't meter as easily, sometimes requiring a little jostling to get charges through the tiny neck. However, Accurate LT-32 is also more temp-resistant than 1680, and despite being an extruded powder the granules are tiny enough to meter easily. Accurate 2200 also does pretty well with 20-grain bullets in a pinch, and is a good choice for those who prefer 25-grain bullets, along with H322, Norma 200 and RL-7.
Hi John, good to see you've stuck with the sweet little .17HH. I bought one in April of this year. Like you, I found that the factory stuff was outstanding and also cheaper to shoot than buying all the components initially. I've since accumulated about 400 brass, all of them from factory loads except one box of 50. My intention all along was/is to reload, but man, that Hornady factory stuff shoots amazingly well.
I was out to the range today with a box of factory loaded 20gr VMax, as well 50 handloaded 25gr, half Rem HP power-lokt, the other half VMax. Until today I've been using only Lil Gun as 1680 appears to be unobtainium here in Canada. But the Lil Gun is just too volatile, and I've never been able to achieve consistent, reliable pressure or accuracy. It is extremely temperature sensitive stuff. Last time out to the range, a couple weeks back, and chronographing 3 shot strings, the first two would be within 5-10 fps of each other (~3720) and the third shot would jump by 100fps. This happened with more than one string; I concluded that after the first two shots, the chamber was heating up sufficiently that the third shot would be crazy.
All that to say that today's loads were with H4198. The groups I was getting were consistent with what I've come to expect from the 17HH (.75 at 200yds). What a difference! I think I'm going to abandon Lil Gun. I have a stash of 750 of the Rem 25grs and would like to work up a consistent, accurate load, working primarily with 4198 and RE7. What do you think? And what has your experience been with the 20 grainers using powders other than 1680?
BTW, I had some factory 20gr VMax with me today; I use it as a baseline if I'm getting erratic results with my handloads to make sure my scope, etc, are OK. I thought I would foul my bore (cleaned my rifle this morning before going to the range) before clocking my handloads. Less than .25" at 100yds for 3 shots, which is typical of this stuff.
