The snap might have come from a whip, or a flag in sharp wind. The missile sped fast as a wish, but the rifle barely hopped. Downrange, light winked through a hole too small to see through strong glass. I crossed the creek and sage flat to look. The last of five bullets had held the group to 0.6 inch.

I had fired 10 rifles that week, all bored for the then-new .17 Hornady Magnum Rimfire. From Anschutz to Ruger, all nipped teeny 100-yard groups. Three yielded sub-MOA averages for five, 5-shot strings! An entry-level Savage lasered a 0.34-inch knot! 

Such accuracy across a spectrum of affordable sporters astonished me. Clearly, Hornady’s ammo was exceptional. And factory barrels for the .17 HMR were much better than a glance would indicate. 

Now, more than 18 years later, the HMR is old news. Other .17s, rimfire and centerfire, have followed. But the plunge into sub-smallbores began on handloading benches decades ago. Wildcatters chasing higher velocities necked the likes of the .22 Hornet and .218 Bee to take .172-inch bullets, reducing case taper and abbreviating necks above steeper shoulders. Bullet-makers R.B. Sisk (TX), F.N. Barnes (CO) and Ted Holmes (IL) marketed the tiny missiles. Enthusiasts rolling their own turned to Speer for jackets. Fred Barnes built bullets as heavy as 45 grains for fast-twist barrels. With a compressed charge of IMR 4198 in the .17 Hornet, P.O. Ackley accelerated 25-grain spitzers to more than 3,500 fps – sizzling speed in the 1950s. He observed this load was “extremely deadly on small game” as stout as foxes. 

Among the best received .17s of the time came from the O’Brien Rifle Co. of Las Vegas. Its copyrighted name: .17 Mach IV. O’Brien used a .223 case cut to 1.40 inches. The same result can be achieved with the .221 Remington Fireball, given minor changes to lengthen the neck and bring shoulder angle to 30 degrees. The Fireball, a shortened .222 Rem., was developed for Remington’s XP-100 bolt-action pistol in 1963. The success of its .17 progeny among handloaders would prompt Remington to trot out a commercial version, the .17 Fireball, in 2007. It spits 20-grain bullets at 4,000 fps.

In Remington’s Model 700 rifle, the .17 Fireball replaced the .17 Remington, a 1971 introduction on the .223 hull that sent 20-grain AccuTips at 4,250 fps and 25-grain hollowpoints at 4,040. Pelt hunters liked the .17 Remington because its frangible bullets disintegrated inside, leaving hides intact.

Alas, angst over throat wear and fouling tarnished the round in print. The .17 bore was still new to shooters. The great unwashed hadn’t considered the cost of blistering speed or sought out skinny rods and special brushes to scrub bores the size of goose shot. Fastest .17 commercially loaded, the .17 Remington remains on that company’s ammo roster. Its 20-grain bullet beats even the .204 Ruger’s 32-grain off the blocks, with 45 percent less powder! Cleaner propellants and moly-coated bullets now mitigate fouling. Letting barrels cool between shots at the bench or in sod poodle colonies goes far in throttling throat erosion. 

I’m sweet on the more efficient .17 Fireball, and on Hornady’s version of the .17 Hornet, released in 2012. Despite its ancient origins and modest dimensions, this is a frisky rascal, hurling a 15-grain NTX at 3,880 fps, a 20-grain V-Max at 3,650! I just bought a CZ 527 in .17 Hornet. This cute, compact sporter has an action perfectly proportioned for the cartridge. 

Ruger has also chambered its 77-Series rifles in .17 Hornet. The 77/17 is unique to date, as it also comes in .17 Winchester Super Mag, a rimfire round developed by Winchester and Mike Bussard and introduced in 2013. Rim and body dimensions bring to mind the obsolete .25 Stevens; but the .17 WSM is based on a 27-caliber nail-driving blank! Its heavy brass brooks 33,000 psi, pressure 21 percent higher than generated in the most rambunctious of other modern rimfires. With 20-grain bullets clocking 3,000 fps, and 25s at 2,600, the .17 WSM registers 400 and 375 ft./lbs. of energy – 2 1/2 times as much as the .17 HMR. Rifles in .17 WSM have 1:9-inch rifling (most barrels for centerfire .17s are rifled 1:9 or 1:10).

Oddly enough, Savage was the first company to offer rifles for Winchester’s .17 Super Mag. The B.Mag has a rear-locking, cock-on-close bolt, a rotary magazine and Savage’s AccuTrigger. Stranger still, this is the second Winchester cartridge rescued by Savage! The .22 Hornet, developed by G.L. Wotkyns, Townsend Whelen, G.A. Woody and A.L. Woodworth, joined Winchester’s ammunition roster in 1930, before any rifles were so chambered. Savage listed the first .22 Hornet rifle, its M23-D, in 1932!

The fortunes of any .17 rimfire are shackled to the hugely popular .22 Long Rifle, which dates to 1887. It quickly upstaged the .22 Short (1856) and .22 Long (1871). The .22 Remington Special and .22 Winchester Rimfire (WRF), on the eve of smokeless powder, proved no competition for the .22 LR. Nor did the .22 Winchester Magnum Rimfire (WMR) in 1959. Many millions of Long Rifle cartridges tumble off the line each year in facilities that depend on high volume to defray frightful up-front costs. 

Hornady Takes a Chance

The math was surely on Steve Hornady’s mind 20 years ago when Hornady engineer Dave Emary showed him a .17 cartridge he’d developed on the .22 WMR case – a project whose roots date to 1989 at Federal, and exploratory work by Steve Chernicky.

Loaded commercially with 17-grain .172-inch poly-tipped spitzers, the .17 HMR costs much more than the .22 LR to produce. “Shooters accustomed to cheap .22 ammo will have to want this .17,” Dave told me then. “It has no chance as a stand-in for the Long Rifle.” 

Hornady’s modern, high-capacity centerfire factory couldn’t deliver rimfire cartridges. The HMR would have to be loaded on existing equipment elsewhere. 

“The smallest initial order CCI would accept was five million rounds,” says Steve Hornady, “and we had to buy plates to load 1,200 hulls at a time!” He took the plunge. Apprehensions vanished when almost immediately Hornady logged orders totaling 12 million cartridges! My range tests, and reports from predator and varmint shooters, confirmed the results of lab trials. This was a wonderfully capable cartridge, flat-shooting and deadly on small game, and much more accurate than its parent .22 WMR.

Shooters bought 146 million .17 HMR rounds in 2003, the year after its debut! Emary and CCI engineer Brett Olin began work on a standard-length .17 rimfire to follow. It emerged as a necked-down CCI Stinger. Hornady patented the design, trademarking it the Mach 2. 

“Dave wanted a 25-degree shoulder,” Brett told me. “But 20 degrees made more sense in manufacture. That tiny neck gave us fits blowing fulminate into the rim, so we necked hulls after priming.”

Faded Rose

The bloom on the Mach 2 rose has faded a bit — partly because this cartridge followed the faster, flatter .17 HMR, partly because its hunting application is pretty much limited to that of the.22 LR.

While Federal and Winchester have introduced .17 HMR loads, only Hornady at this time makes Mach 2 ammo. Ballistically, the quick-stepping .17 HMR trumps its .22 WMR forebear. With a 100-yard zero, a 40-grain JHP from the .22 WMR sags 6 inches at 150 – double the 3.1- inch drop of a 20-grain .17! But poly-tip bullets have improved the accuracy and extended the reach of the WMR. I’ve found its heftier bullets an asset on the sturdiest small game. 

Like the .22 WMR, the .17 HMR does not like self-loading rifles. 

“Fixed-breech actions give you latitude in burning rate,” Dave Emary told me. “In self-loaders pressure curves matter more. A steep peak moves the bolt too suddenly; if high pressure remains as the bolt opens, the case may bulge.”

The .17 WSM adds thump. For predators, its 375 ft./lbs. of muzzle energy from 20-grain bullets give you a clear edge over the 250 ft./lbs. for same-weight bullets in the .17 HMR. The energy gap widens at distance. My tests show lightweight bullets in .17 rimfires deliver fine accuracy, but the heavier options excel for hunting. They hit harder up close and better hold their energy and deflect less in wind. 

Centerfire .17s have a few advantages over their .22 counterparts. The most vaunted being the negligible recoil (so you can watch your target crumple or erupt) and a faster exit (for flatter flight at least to mid-range).

But that slender case neck limits bullet weight. And ballistic coefficients of the sleekest .17 bullets hover around .190. Figure on quick capitulation to drag. You’ll not readily kill big animals with .17s or reach as far as beefier .22 spitzers.

Still, .17s have a place, and in some cases upstage .22s. Launching tiny bullets at Mach 4 into teeny groups is great fun — and solace when predators lie low.