Behind the Bullet: .17 Winchester Super Magnum

posted on December 18, 2023
BTB 17 WSM Lead

More often than not, a young shooter will be introduced to the practices and mechanics of marksmanship with a rimfire rifle in hand. And, while the .22 Long Rifle continues to sit atop the throne when it comes to choices of rimfire cartridges, not all rimfires are created equally. Winchester sought to improve on the velocity of the .22 LR over 60 years ago with the advent of their .22 Winchester Magnum Rimfire, and Hornady took things even further with the 2002 release of the .17 Hornady Magnum Rimfire, necking down the .22 Mag to hold .172-inch-diameter bullets. But if velocity is your thing, and you want the speediest rimfire cartridge currently available, look no further than the .17 Winchester Super Magnum—or .17 WSM for short.

American Eagle 20-grain .17 Winchester Super Magnum ammunition.

Released in 2012 and developed in conjunction with Savage rifles, the .17 WSM’s case is based on a .27-caliber nail gun blank, necked down to hold 20-grain .17-caliber projectiles. It’ll drive those little bullets to 3000 fps, offering a very flat trajectory, much to the chagrin of woodchucks, prairie dogs, and other varmints. The case is much thicker than other rimfire cases—roughly twice as thick as the .17 HMR and .22 WMR—and accordingly the .17 WSM is loaded to a higher pressure, right around 33,000 psi. With a 20-degree shoulder and a case length of 1.200 inches, the .17 WSM is the longest of our rimfire cartridges, yet is still shorter than the Hornet family of centerfire cartridges.

Current factory loads feature that 20-grain bullet cruising at 3000 fps, a 25-grain bullet at 2600 fps and a lightweight 15-grain bullet at 3300 fps. Comparing the cartridge to others in its class, the centerfire .17 Hornet launches a 20-grain bullet at 3650 fps, and the rimfire .17 HMR sends that same projectile at 2375 fps, so the .17 WSM represents a good balance of rimfire convenience (rimfire ammo is generally less expensive than centerfire stuff) and respectable velocities.

Looking at the trajectory of the 20-grain load—the most popular—and you’ll find that with a 100-yard zero, the bullet will strike 1.2 inches low at 150 yards, and 4.1 inches low at 200 yards. At the 200-yard mark, the bullet is still moving at over 2000 fps. I’d personally opt for a 150-yard zero, as it would offer a dead hold to about 175 yards, unless you’re head-shooting squirrels. Comparing this trajectory to the next speediest rimfire—the .17 HMR—and you see that with a 100-yard zero, the Hornady cartridge drop 9.9 inches at 200 yards; the WSM cuts that drop in half. Compare the .17 WSM trajectory to that of the .22 LR with a 100-yard zero, and the classic 40-grain load will drop 12 inches at just 150 yards. If you want to do some long-range hunting for varmints using a rimfire, the .17 WSM is certainly an attractive option.

Rimfire rifle with .17 WSM ammunition on outdoor shooting bench.

I got to spend a week with the .17 WSM in a wonderfully target-rich environment a while back; it was among several rimfire cartridges brought along on a prairie dog eradication operation on the famous Rosebud Reservation of South Dakota. Any unfortunate rodent who paused for more than few seconds inside of 250 yards didn’t stand a chance, and most died in a cloud of red mist. I had the opportunity to take the cartridge out to 300 yards and a bit more, and came away very impressed with its performance. That velocity level certainly does heat the barrel up quickly, and in the rapid-fire situation that a hot prairie dog town will present, there were several times I had to let the Savage rifle cool down. All things considered, I feel the .17 WSM makes a great varmint cartridge, though I have not had the chance to use it on larger predators like foxes or coyotes. Friends have done just that, with mixed results; some felt it handled bigger-bodied male coyotes just fine, and others felt that the WSM didn’t hold them well enough. Maybe there are better tools for hunting coyotes, but seeing as I’ve killed them cleanly with a .22 Long Rifle, I’d wager that a properly placed shot would work fine. Perhaps coyote hunting with the .17 WSM warrants choosing the heavier 25-grain load, despite the lower velocity figure.

Factory loads have been—historically speaking—available from Winchester, Browning, Hornady and Federal (under their American Eagle brand). However, both the Hornady and Federal loads have been discontinued, and to make matters even worse, the Browning load has also gone the way of the dodo. Winchester’s three loads are all still catalogued, yet I am not alone in seeing that none of them seem to be on shelves. Though barely a decade old, the .17 WSM seems to be lower on the totem pole than I’d care for it to be—I really like this cartridge. Hopefully the lack of available ammunition is only a temporary condition, as supplies are still reeling from the shutdown of 2020 and then the incredible demand put on what supplies we had by millions of new shooters coming onboard.

Hornady 20-grain V-Max .17 WSM ammunition.

Despite the magnum-level velocities, the recoil of the .17 WSM is still next-to-nothing, and actually allows a new shooter to learn some long-range shooting skills without punishment. Street prices of ammunition runs about $0.40/round (about the same as the .17 HMR stuff), so while it isn’t as cheap as shooting a .22 LR, it is less than half the cost of shooting the .17 Hornet, which I also enjoy shooting. Undoubtedly, the .17 HMR has taken root, with nearly all major manufacturers offering ammunition for that, though the younger .17 Mach II seems to be all but completely gone, and I’m really hoping that the .17 WSM does not follow suit. Only time will tell, but I know the design is both accurate and effective for any species you’d pursue with a small-caliber rimfire.

Looking for previous installments of our "Behind the Bullet" series? We've got you covered.
350 Legend
.303 British
26 Nosler
6mm Remington
.270 Winchester Short Magnum
360 Buckhammer
30 Nosler
7-30 Waters
.370 Sako Magnum
.17 HMR
6.5 Weatherby RPM
.327 Federal Magnum
.450 Bushmaster
7mm PRC
.275 Rigby
.340 Weatherby Magnum
.416 Ruger
27 Nosler
.257 Roberts
7mm Weatherby Magnum
 .300 PRC
.350 Rigby Magnum
.450 Nitro Express
.17 Hornet
7mm STW
6.8 Western
.375 Ruger
.223 Remington
• 6.5x55 Swedish
.416 Remington Magnum
.300 Winchester Short Magnum
28 Nosler
6.5 PRC
.22 WMR
.458 Winchester Magnum
.22 Hornet
.280 Ackley Improved
.240 Weatherby Magnum
.458 Lott
• .264 Winchester Magnum
• .348 Winchester
33 Nosler
• .260 Remington
• .30-30 Winchester
• .416 Rigby
 .358 Norma Magnum
• .22 LR
• 7mm-08 Remington
• 8mm Remington Magnum
• .338 Federal
• .224 Valkyrie
• .338-06 A-Square
• 9.3x62mm Mauser
• .257 Weatherby Magnum
• .45-70 Government
• .300 H&H Magnum
• .25-06 Remington 
• .30-06 Springfield
• 6.5 Creedmoor
• .300 Remington Ultra Magnum
• 7mm Remington Magnum
• .470 Nitro Express
• .280 Remington
• .300 Winchester Magnum
• .270 Winchester
• .222 Remington
• .45 ACP
• .404 Jeffery
• .44 Remington Magnum 
• .41 Remington Magnum
• .243 Winchester
• .338 Winchester Magnum
• .357 S&W Magnum
• 6.5-284 Norma
• 8x57 Mauser
• .38 Smith & Wesson Special
• 7x57mm Mauser
• 9mm Luger
• .35 Whelen
• .454 Casull
• .375 H&H Magnum
• .45 Colt
• .22-250 Remington
• 10mm Auto
• .308 Winchester


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