Reloading the .17 Hornet

The .17 Hornet is arguably the best balanced of all the .17 cartridges, wildcat or factory. P.O Ackley is credited with introducing the first .17 based on the Hornet case; the .17 Ackley Hornet was basically the K-Hornet necked down to fire a .172-inch bullet. Over the years, however, a few problems became apparent. Capacity of Hornet cases varied quite a bit, because of the varying thickness of the brass. This made handloaders extremely wary about mixing different brands of brass. But that was not the only problem.

Aussie handloaders struck trouble with their Brno ZKM 465 Hornet rifles back in the early 1950s. SAAMI specs call for the Hornet case to measure .300-inch at the web, (in front of the rim). For some unknown reason, Winchester and Remington cases measured .292-inch and sometimes smaller. The solution to this is rather simple. Custom gunsmiths used an undersize reamer so that cases matched the chamber.

Some of the European ammo makers made brass cases that were not only larger but had thicker rims. When owners of Brno Hornet rifles used American ammo in their rifles, the fired primers protruded – a sign of excessive headspace. Another problem: the capacity of different brands of Hornet cases varied quite a bit owing to the varying thickness of the brass. For this reason when reloading .17 Ackley Hornet cases, experienced handloaders took extra extra care not to mix brands of brass.

When reloading the Hornet case, firing it, resizing and firing again the heads were prone to separate after only two or three firings. Years ago, Kimber found this to be a real problem, and I’m sure it’s one the reasons that they dropped the .17 Ackley Hornet and .22 Hornet from their calibre line.

Hornady’s new .17 Hornet ammunition does away with all the dimensional problems that plagued owners of wildcat .17 Ackley Hornet rifles. Although somewhat similar, the .17 Hornet is not identical to the old Ackley wildcat. The cartridge’s overall length of 1.723-inches, is exactly the same as the parent .22 Hornet, but the case is slightly shorter – 1.3500-inch against 1.400-inch. And the neck is shorter too – 0.182-inch against 0.225-inch for the Ackley version. The factory .17 Hornet has a gentle 25-degree shoulder angle instead of Ackley’s sharper 33- degree angle, together with less body taper – 0.006”. Brass at the mouth of the case is 0.010-inch thicker too, which makes the case better able to stand up to repeated reloading. Made of heavier brass, the .17 Hornet case has a nominal water capacity of 14.7 grains, or slightly less than the .17 Ackley which is rated at 15.1 grains However, the capacity does change by up to 0.6 grains after being fired and even after being full-length resized. However, for all practical purposes, such minor differences can be ignored.

As a medium range varmint cartridge, the .17 Hornet’s ballistical performance is fine inside 250 metres. While the 20gn V-Max has a low sectional density (0.097) and ballistic coefficient (0.185), the 25-grainer (S.D 0.121 and B.C 0.187) is only slightly better ballistically than the .224 calibre 40gn V- Max which has an S.D of .114 and B.C of .200. But I’d not go any heavier than 25gn and moving up from a 20gn bullet to one weighing 30-grains offers no advantage because the 50-percent increase in weight results in a significant lowering of velocity. Also, if you use the heavier bullet, the wind has more time to work on it, because of the longer time of flight. In my original Remington Model 700 in .17 Remington I used 22.5gn of AR2208 to drive the 30gn bullet at a handy 3780fps, but in the smaller capacity .17 Hornet case the best I could manage was 3025 fps because the 30-grainer’s length takes up a lot more of the already limited powder space. Nor is it possible to seat the bullet closer to the lands, because the length of the magazine restricts cartridge overall length to 1.723-inch.

According to Hornady’s Dave Emary, the .17 Hornet was designed around the company’s 20gn V-Max bullet and a 1:9 twist is ideal. He says” The 20-grainer has a longer ogive than the 17gn .17 HMR bullet and a much higher ballistic coefficient, (.185 against .128) which results in higher retained velocity downrange.

There’s a choice of bullets in 20, 25 and 30gn weights and 12 different bullet types from Berger, Hornady, Nosler and Remington. Polymer tipped or hollow-pointed, they’re all designed to expand readily against light resistance. All have a relatively low sectional density and ballistic coefficient, the equivalent of a .308 bullet that weighs 95 grains, which means they slow down real fast over the long haul.

The maximum average chamber pressures permissable for .22 Hornet brass is 47,000 psi, and the thin-walled cases will be ruined very quickly if pressure limits are exceeded. This figure also holds true for the wildcat .17 Ackley Hornet, but evidently the new .17 Hornet case is capable of withstanding a SAAMI maximum average pressure of 50,000 psi. If the handloader follows Hodgdon’s data and loads the case to an average 48,000 psi, case life should be extended. The cartridge headspaces off the rim, but Hornady tightened up the chamber at the shoulder to reduce cases lengthening.

Handloading the .17 Hornet was quite an experience. When working with such a small cartridge, all cautionary advice and warnings that apply to reloading in general apply double to the.17 Hornet. A grain or so added powder doesn’t mean much in an ‘06 capacity case, but in the .17 Hornet even one-quarter grain can make a big difference in the ballistical properties of the cartridge. When approaching maximum loads, 1/4-of-a-grain can suddenly send pressures through the roof. For that reason I strongly recommend weighing and not measuring all powder charges.

Like the .17 Ackley Hornet the .17 Hornet is sensitive to minute changes in powder charges and seating depths, so caution is indicated. I seated all bullets out as far as practical within the limits of the rifle’s magazine. According to the chamber dimensions of the Model 25, the maximum permissable brass length is 1.363 and the “trim-to length (reached after four or five firings) is 1.3500”. Hornady lists the Cartridge Overall Length as being 1.720-inch.

Hornady Custom full length sizing die made resizing lubed cases easy, but one should always take extra care to avoid damaging case mouths when inserting the expander button. I used a Sinclair hand priming tool to seat primers against the bottom of the pockets. The bullet seater die uses a floating sleeve to align the bullet with the case mouth; this is a pious idea, but try to hold the bullet level with the case mouth until it enters the sleeve to avoid seating a bullet cockeyed. Even when a propellant charge filled the case and had to be heavily compressed, Hornady’s seater stem seated all the different shaped bullets without any damage to their points.

The .17 Hornet’s factory velocity of 3650fps was achieved using Superformance powders, a special class of spherical propellants that have been chemically and mechanically adapted to maximize velocities. Two different Superformance powders used to load Hornady .17 Hornet ammo give 150 to 200 fps better performance
over standard powders.

Us mere mortals are obliged to use the standard canister powders used by Hornady and Hodgdon to develop loading data for the .17 Hornet. These included Alliant 2400 (which lies between WIN-296 on the faster side Lil’ Gun and AR2207 on the slower end), N110, VIHT N-120, VIHT N- 130, WIN-296 and AR2207. I had no 2400 or N-120, so I used the powders that were available to me – AR2205, BM-2, Lil’ Gun, WIN-296, Viht 110, Viht N-130, IMR 4198, AR2207, AR2219, and threw in Re-7.

While Hornady lists data for WIN-296, I expected it to be quickly eliminated because despite being an outstanding performer in the .22 Hornet, WIN-296 has gained a reputation for performing erratically in bottleneck cases like the K-Hornet, giving fluctuating pressures. Being a fine ball powder, W-296 is seen at its best with charges that have a high load density and almost fill the case. Nothing untoward happened with the .17 Hornet, WIN-296 was on its best behaviour and it proved one of the best propellants. However, if anyone has any doubts about safety issues when using Win-296, I suggest they give it a miss. All of the other powders worked well with 20 and 25gn bullets. Velocities varied but the accuracy level was almost identical, with the edge going to Lil Gun. All testing was carried out using CCI-450 small magnum primers.

Data available from Hornady and Hodgdon for the .17 Hornet simplified my own experimenting. Ackley’s Handbook for Shooters and Reloaders Volume 1 lists loads for the .17 Ackley Hornet with old Du Pont powders, but I’d recommend against attempting to duplicate any of those as the .17 Hornet has 5-percent less case capacity.

When assembling test loads, increasing the powder charge two-tenths of a grain at a time proved the best way to go, at least during the initial stages. As maximum loads were approached in the Savage Model 25, bolt lift never became sticky, nor did case expansion become measurable, indicating a chamber with minimum dimensions.

The most accurate loads have been with the Hornady 20gn and 25gn V-Max bullet which turned in 3-shot groups averaging .50-MoA. My best load with the 20gn V-Max was 10gn of Lil Gun for a sizzling 3699fps, but 10gn of AR2205 gave a handy 3535fps and WIN-296 did 3550fps. Like the larger Remington .17s, the .17 Hornet seems to build up peak pressures rather quickly. Slight overcharges will probably cause leaking primers, so it’s a good idea to err on the cautious side. Also, thick cup primers such as the Remington 7-1/2 and CCI 450 should be used exclusively. Since 1972 all CCI 400 and 450 primers have been made with .023” cups and while the hotter 450 Magnum primer is not needed to ignite the small powder charges in the .17 Hornet I thought its extra brisance worthwhile to ignite heavily compressed charges. Standard small-rifle primers are likely to pierce or “biscuit cut” the firing pin indent.

I seated bullets so as to fit easily in the magazine and made no attempt to adjust them so as to just miss contacting the lands. Unprimed brass received the usual treatment, necks were squared and uniformed with my Forster Case Trimmer and chamfered lightly. This is not one of those rounds where the reloader needs special Superformance powder to equal factory velocity, it can be done with available powders as you can see from the load table.

Hornady ammunition is affordable at around $33 for a box of 25, but its not a .17 Remington, or anyway near a .22-250. While it does shoot as flat as a .223, it’s going to be buffeted about more by even the gentlest breeze, and those light bullets don’t deliver anywhere near as much energy. For picking off rabbits and foxes out to 200 metres or so, it’s an amazing fun gun.

By my rule of thumb, 250 metres is the maximum distance to be shooting at varmints with the .17 Hornet since velocity peters out pretty fast and the light 20gn bullet is travelling at only 2000fps at 300 metres where it delivers little more punch than the .22 Long Rifle bullet has at the muzzle. In the wind the flyweight bullet gets blown off course just a bit more than the slower, heavier bullet from a .222 – 284mm at 250 metres in a 16 kph wind.

The .223 Rem. driving a 55gn bullet at 3200fps sighted-in 50mm high at 100 metres for a 200 metre zero, shows only 25mm more drop at 250 than the .17 Hornet but retains 565 ft/lb of energy which gives it over twice as much hitting power as the .17 Hornet over the same distance.

Reloading this small case calls for extra care and awareness. I received a set of Hornady dies and a box of 20gn and 25gn V-Max projectiles from Herron Security & Sport several weeks before the rifle and ammo arrived. I also had seven hundred obsolete 25gn Remington Power Lokt hollow-points that I’d been saving for a rainy day. These bullets often keyholed when driven out of the .17 Remington at top velocities, because when loaded too hot, the jacket material often stripped causing the bullets to tumble in flight. I found this could be avoided, either by reducing velocity or using the Hornady 25 grainers. Being thin- jacketed made the Remington bullet an excellent performer in the .17 Hornet where speeds rarely exceed 3400fps. The same charge weights of different powders delivered identical velocities and accuracy with the 25gn V-Max as the Remington Power Lokt bullet.

In the past I’ve found that the lighter bullets work best in 1:11 or 1:12 inch slow twist barrels, but often a 1:11 twist will cause 25gn bullets to keyhole. When Remington introduced their 17 Remington they very sensibly used the faster 1:9” twist, which is what the new Savage 25 and Ruger 77/17 have.

A fox is just about the top end of the scale for the .17 and it will lower the boom on them consistently out to 200 metres. However, I cannot recommend the .17 Hornet for animals the size of goats and pigs. These game animals stretch the performance of the 25gn bullet to the point where it becomes inconsistent. The risk of a wounded animal running off to die a slow, lingering death is extremely high and no ethical hunter would ever countenance that.

From the perspective of handloading, the.17 Hornet and the Savage 25 make a nice combination. Suppose we first consider accuracy. Lil’ Gun immediately stands out, having been used in the loads that produced the highest velocities and cut the tightest groups. Second placegetter was WIN-296. Factory ammo costs around $34 for a box of 25 and unprimed brass $30 for 50. Cases should be good for 10 reloads or more.

The tough Hornady brass will withstand a good many reloadings, most of them either full-power or close to it. But after four reloads my .17 Hornet brass gradually lengthened and I trimmed them to 1.335” which is 0.015” below the standard length of 1.350”. Thereafter, the rate of stretching slowed noticeably, cases lasted through numerous reloadings before a second and final trimming became necessary.

Summing up: the Savage 25 is well made with a strong, rigid action and a stable laminated stock that will maintain a constant zero. The .17 Hornet is a fine mid-range varminter that is capable of reaching out 250 metres to handle 90-percent of all varminting chores, and allows the shooter to call his shots through the scope. It isn’t as hard on barrels and far less susceptible to fouling and requiring frequent cleaning than the larger-cased .17 Remington Fireball and .17 Remington. But I’ve saved my best news for last; you’ll get up to 700 loads from a single canister of powder; you can’t get a cartridge that’s more economical than that.


This article was first published in Sporting Shooter Magazine May 2013.




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Nick Harvey

The late Nick Harvey (1931-2024) was one of the world's most experienced and knowledgeable gun writers, a true legend of the business. He wrote about firearms and hunting for about 70 years, published many books and uncounted articles, and travelled the world to hunt and shoot. His reloading manuals are highly sought after, and his knowledge of the subject was unmatched. He was Sporting Shooter's Technical Editor for almost 50 years. His work lives on here as part of his legacy to us all.


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