Though it was immediately popular upon its release and was arguably the only successful rimfire cartridge design to come out of the 20th century, the venerable .22 Winchester Magnum Rimfire has spent recent years in the shadow of its cheaper, more popular cousin, .22 Long Rifle, along with newer, snappier cartridges like .17 HMR.
But does .22 Magnum - once the quintessential ranch gun and varminting cartridge - still have a place? We’re going to take a look at the history of this cartridge, its ballistic performance, and the applications it excels at – and whether it’s an option worth considering for the modern shooter.
The .22 Winchester Magnum Rimfire cartridge, often abbreviated .22 WMR or .22 Mag, was first developed in 1959 by the Winchester Repeating Arms Company as a way to bridge the gap between the popular .22 Long Rifle cartridge and centerfire .22 options of that era.
Because .22 Magnum is an elongated version of its .22 Winchester Rimfire (WRF) parent case, a gun chambered in .22 WMR is fully capable of firing .22 WRF - though many magazine-fed .22 Magnum autoloaders have trouble feeding the shorter WRF cartridge and would require each round to be chambered manually. That also means that a .22 WMR firearm can fire .22 Remington Special, which is identical to Winchester Rimfire except for having a pointed bullet instead of a flat-nosed one.
However, keep in mind that a firearm chambered in .22 Magnum cannot safely fire .22 Long Rifle cartridges - even though the bullet diameter is the same, the differences in case dimensions would result in split cases, escaped gases, and potential damage to the chamber throat.
Ironically, though Winchester designed the cartridge itself, they were one of the last major firearms manufacturers to produce a firearm that was actually chambered for it – by the time Winchester began selling their Model 61 slide-action rifle, Smith & Wesson and Ruger had already put .22 WMR revolvers into production, and both Savage and Marlin were able to able to adapt existing rifle designs to the new cartridge quickly enough to beat Winchester to the punch, as well.
Compared to .22 LR, the longer, wider, and thicker case dimensions of .22 WMR allowed for hotter grain loads and higher chamber pressures, and its original 40-grain, .224-inch diameter bullet boasted a muzzle velocity of 2,000 feet per second.
In short, .22 WMR offered a faster, flatter-shooting round with improved penetration and expansion, quickly establishing itself as an excellent varmint cartridge ideal for hunting small game out to about 130 yards in skilled hands.
Though .22 WMR was initially loaded with a blunt-nosed 40-grain bullet, commercial loads are now available ranging from 30 to 50 grains, and more aerodynamic polymer tips are offered by manufacturers such as Remington, CCI, and Hornady. Because a 30-grain bullet was found to offer the optimal balance of velocity and energy, it’s the most common .22 WMR ammunition you’re likely to come across, and the one we’ll use to look at the cartridge’s ballistic profile.
As you can see, the round sheds velocity relatively quickly and begins to experience significant drop past the 125-yard mark, though making accurate shots out to 150 yards is still entirely possible. In the 75-100 yard sweet spot, .22 WMR is a remarkably fast and flat-shooting cartridge, and at 100 yards it is still delivering just over 140 foot-pounds of energy.
Of course, .22 WMR performs optimally out of a rifle barrel, but the cartridge is still able to maintain roughly 80% of its muzzle velocity when fired from a handgun, making it a popular choice for revolver enthusiasts who can quickly swap between .22 LR and .22 WMR with the use of a convertible cylinder kit.
.22 WMR vs. .22 LR
Because .22 WMR was designed to improve upon .22 Long Rifle for the purposes of hunting and varmint control, it’s also worth comparing the two cartridges side by side.
.22 Winchester Magnum Rimfire outperforms .22 Long Rifle in terms of trajectory, speed, and energy on target – at 50 yards, .22 WMR boasts 215 foot-pounds of energy compared to .22 LR’s 113 foot-pounds, and that difference becomes even more stark when comparing heavier bullets: each using 40-grain bullets, .22 WMR boasts twice as much kinetic energy at 100 yards as .22 LR has at the muzzle.
.22 Magnum’s less dramatic drop-off and significantly higher kinetic energy make it a superior short-to-medium range hunting cartridge, and it’s more than capable of ethically bagging small game such as rabbits, squirrels, raccoons, and coyotes with more margin of error in shot placement than .22 LR allows.
While you might get a bit of bloodshot meat on very small game, it’s still a far cry from the damage that a centerfire .22 cartridge would cause, which makes it an excellent choice for varmint hunters who want to tackle a versatile range of game while keeping ruined meat and pelts to a minimum.
While .22 LR remains the undisputed champ when it comes to cheap plinking ammo, .22 Magnum’s flatter trajectory and superior ballistic coefficient make it the better choice for shooters who are interested in precision target shooting or rimfire competitive shooting events.
And while it may not be as cheap as .22 LR, a trip to the range with a few boxes of .22 WMR won’t break the bank, either, which is good news for those of us who prefer to practice with the exact same equipment that will be used in matches.
Varmint / Pest Control
As we’ve seen from the ballistic comparisons, .22 WMR packs quite the punch for its size, and the same qualities that made it instantly popular as a hunting cartridge also make a rifle or handgun chambered in .22 WMR an excellent choice for a do-it-all ranch gun.
Standard loads are more than capable of dispatching common pest animals such as groundhogs, gophers, prairie dogs, and foxes, and CCI produces ammo loaded with No. 12 shot that are ideal for handling snakes, mice, and rats without fear of overpenetration.
At the end of the day, .22 Winchester Magnum Rimfire is a great little cartridge that has stood the test of time and carved out a niche for itself in the world of rimfire hunting calibers.
While it may not be as cheap as .22 LR, and while more modern rounds like .17 HMR may have slightly edged it out in terms of velocity and effective range, .22 WMR is still the cartridge I would turn to if I wanted a versatile rifle that was inexpensive to shoot, soft on the ears, capable of handling larger varmints like coyotes, bobcats, and foxes, and was still accurate enough to punch ¾” groups at 100 yards without much fuss.