Hornady’s .17 Hornet Delivers Versatile Varmint Performance.
The first modern .17-caliber cartridges were all wildcats, primarily because no major bullet company made anything to fit the tiny bores. Among the first was the .17 Hornet, essentially the .22 K-Hornet necked down.
The K-Hornet got its initial from Lysle Kilbourn, an upstate New York rifle enthusiast credited with being the first to “improve” a cartridge by firing it in a larger chamber. The original .22 Hornet was developed from the old black-powder .22 WCF round, differing only slightly in dimensions, but when a Hornet case was fired in a K-Hornet chamber, the very sloping shoulder was blown forward to a much sharper angle, increasing powder capacity. I had a K-Hornet for a while, a rechambered CZ 527, and it developed around 200 feet-per-second more than the standard Hornet, a considerable increase.
In the early 1950’s, famous gunsmith P.O. Ackley essentially necked down the K-Hornet case to .17 caliber. (He may have increased the shoulder angle slightly to the 40 degrees now known as the mark of “Ackley Improved” cartridges, but various sources quote all sorts of shoulder angles for both the K-Hornet and the .17 Ackley Hornet.) An early advocate of both the .17 bore diameter and high velocity, Ackley claimed muzzle velocities of up to 3,585 fps with 25-grain bullets, using IMR 4198 powder—but Ackley was also well-known for pushing pressure limits, and the data from his Handbook for Shooters and Reloaders doesn’t list barrel length.
Late in 2011 Hornady introduced a factory version of the .17 Hornet, with a 25-degree shoulder, less tapered case and shorter neck. The dimensions are just small enough that the new round should fit in most .17 Ackley Hornet chambers, but due to the shorter neck the little bullet would have to jump considerably to the lands, probably enough to affect accuracy.
Hornady’s factory load is advertised at 3,650 fps with a 20-grain V-Max bullet, just a little faster than Ackley claimed with 25-grain bullets. There isn’t much difference in powder room between the Ackley and Hornady versions, so I’m guessing that once again P.O. was pushing things.
I’m a .17 fan and wanted one, but it took a while to corral a CZ 527 with a medium-heavy 22-inch barrel. The first range session with Hornady ammo produced several 5-shot groups averaging 0.54 inch and chronographed 3,597 fps. Considering the 2-inch difference between my CZ’s barrel and a 24-inch test barrel, the velocity was right on. Between the accuracy, velocity and single-set trigger on the CZ, the cartridge proved deadly on small varmints out to 250 yards.
Most of the loads tried shot very well in the CZ 527 rifle.
Of course, the next question was handloading, including the possibility of reforming .22 Hornet cases. Due to the .17 Hornady Hornet appearing not long before the latest Obama panic, Hornady ammo and brass weren’t abundant, so many shooters wanted to use standard Hornet brass.
There’s also apparently been some confusion over powder. The Hornady ammo is part of their Superformance line, and Hornady’s website says it’s loaded with Superformance powder. However, Superformance powders in Hornady factory ammunition are cartridge-specific blends.
The Hodgdon Superformance powder available to handloaders is the blend used in .30-06 and some other Hornady ammo, not the blend used for the .17 Hornet. That’s why Hodgdon doesn’t list any Superformance powder data for the .17 Hornet on its website, instead listing several of their faster-burning powders, include Li’l Gun, a powder originally developed for .410 and 28-gauge shotgun loads but also favored by many magnum handgun and .22 Hornet users.
Li’l Gun does work great in the .22 Hornet, especially with 40-grain bullets, filling the case nicely and producing high velocities at much lower pressures than many traditional Hornet powders, helping the relatively thin Hornet brass last much longer. But it’s actually just a little on the fast side for the .17 Hornet, due to the higher capacity-to-bore ratio.
Per usual, I did a “literature search” of all available data before handloading for my CZ .17 Hornet. Due to the very small diameter of the neck, plus the cartridge’s frequent use for high-volume varmint shooting, fine-grained powders work best, especially spherical powders. Luckily, there are a bunch of suitable powders available today.
Before trying any loads, however, I guessed that Accurate 1680 might be the most suitable canister powder for 20-grain bullets. This was due to weighing the powder charges in some factory loads and finding they averaged 12.5 grains, about all the case can hold. The Hornady data for 1680 gave a maximum of 12.4 grains of 1680, for 3,750 fps. In my rifle 12.0 grains matched the factory ammo’s velocity, with very similar accuracy.
A chamfered .22 Hornet case necked down easily in a Redding seating die
with the rod pulled out. The case is then trimmed, loaded and fire formed.
The CZ 527’s medium-heavy barrel and single-set trigger contributed
heavily to John’s accuracy results with the .17 Hornet.
The maximum 10.0-grain load Hodgdon lists for Li’l Gun was the fastest with 20-grain bullets in my rifle, but accuracy wasn’t great, and the velocity considerably faster than the 3,629 in Hodgdon’s data. (Some people also report 10.0 grains is too much in their rifles.) The most accurate load used Vihtavuori N120, but the 10.5-grain charge I tried (0.3 grain under Hornady’s listed 10.8 grain maximum) only got around 3,300 fps, so as it turned out, 1680 was the top powder with 20-grain loads.
Berger 25- and 30-grain bullets were also tested, since some hunters prefer them for larger varmints, especially furbearers. Accurate 2200 did very well with 25’s and Hodgdon H322 with 30’s.
I also tried to develop a specialty load, essentially duplicating .17 Mach 2 rimfire ballistics. The Mach 2 is a nifty little round for both short-range varminting and hunting edible game like tree squirrels and rabbits, but ammo is very hard to find right now due to rimfire manufacturers putting most of their time and resources into .22 Long Rifles as a result of panic buying. I used Accurate’s guidelines for working up reduced loads with 5744 powder, and 7.0 grains got right around .17 Mach 2 velocities with good accuracy. I’d stick to plastic-tipped bullets with these loads to assure expansion at the reduced speeds.
It turned out to be easy to reform Winchester .22 Hornet brass by sizing them in a Redding .17 Hornet seating die with the stem removed. The Hornady version of the .17 Hornet, however, is shorter than the .22 Hornet, so the cases needed to be trimmed 0.06 inch. The formed and trimmed .22 Hornet brass weighed about 10 percent less than the Hornady .17 brass. Velocities with the reformed brass were lower, but pressures probably were too, most likely a good thing with the thinner Winchester brass.
In handloading all three commercial .17 cartridges, I’ve noticed they’re far more sensitive to bullet misalignment in the case neck than any larger caliber rounds. As a result, I used a Redding “S” bushing neck die to resize cases very straightly and a Redding Competition seating die. The results speak for themselves: Every group at 100 yards measured under an inch, and most were much smaller.
Four of John Barsness’s nine books are on firearms and shooting. His latest, Rifle Trouble-Shooting and Handloading, was published in 2012 by Deep Creek Press, and is available through www.riflesandrecipes.com, P.O. Box 579, Townsend, MT 59644-0579, (406) 521-0273.
By John Barsness
Western Powders, Inc.
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