What is the most powerful 22 WMR ammo? Shooters often ask that question when they want to annihilate varmints with alarming efficiency. You might also hear it from gun owners who count on the round for self-defense.

Don’t get us wrong, the 22 WMR is by no means a powerhouse. However, if you shop judiciously you can certainly get a lot of bang for your buck.

What Is 22 WMR?

The 22 Winchester Magnum Rimfire (aka 22 WMR or 22 Magnum) is basically a power upgrade from the popular 22 LR. Both rounds can have essentially the same bullet, although the 22 WMR’s longer and wider case means exactly what you would assume: It holds more propellant, i.e. the stuff that makes a bullet go faster.

 22 WMR22 LR
Parent Case22 WRF22 Long
Bullet Diameter.224".223"
Neck Diameter.242" .226"
Base Diameter.242".226"
Rim Diameter.294".278"
Rim Thickness.05".043"
Case Length1.055".613"
Overall Length1.350"1.00"
Primer TypeRimfireRimfire

A typical 22 WMR loaded with a 40 grain bullet offers a 1,875 fps muzzle velocity (out of a 24” test barrel). A typical 22 LR loaded with a 40 grain bullet offers a 1,200 fps muzzle velocity (out of a 18.5” test barrel). Although these two hypothetical rounds’ bullets weigh the same, the 22 WMR bullet delivers approximately 2.5 times more muzzle energy!

You should know both the 22 WMR and the 22 LR have rimfire primers. Unlike a centerfire primer, which a firing pin hits directly, a rimfire primer is covered by the brass in its case. A rimfire case must not be so thick that a firing pin can’t dent it deeply enough to ignite the concealed primer. (We have an entire guide on rimfire vs. centerfire if you’d like to learn more.)

Here’s why the primer is important: Because its case must be thin by design, a rimfire primed cartridge can never be as powerful as a centerfire primed one. A rimfire primed case is too thin to resist cracking under intense pressure!

What Is the 22 WMR Good For?

All 22 WMR ammo has a design limitation that prevents it from being very powerful. As the result it’s too weak for deer hunting, and may fail to humanely kill an average sized coyote. Many states advise hunters to restrict the use of 22 WMR ammo to game under 20 pounds.

Although nowhere near as powerful as the 9mm and other rounds commonly used for personal protection, shooters often rely upon 22 WMR for self-defense. Its small size permits the design of a very compact firearm – a Cobra derringer weighs a mere 14 ounces. The 22 WMR’s relatively low power also conveys light recoil. You’ll still feel a kick when you fire a 22 WMR handgun, although not nearly as much as one chambered for a smaller centerfire round such as 380 ACP or 38 Special.

What Makes a 22 WMR Powerful?

22 WMR bullet in front of a ballistic gelatin block

Three key factors determine how much damage a bullet can inflict on its target: velocity, mass, and design.

Velocity and mass determine how much energy a bullet strikes its target with. A bullet that is designed for terminal expansion will create a far wider wound cavity than one that isn’t.

The most powerful 22 WMR round would have a fast muzzle velocity, as well as a heavy jacketed hollow point (JHP) or polymer tipped bullet. A weak one would have a low velocity, lightweight full metal jacket (FMJ).

That said, a 22 WMR round doesn’t have to tick all three boxes in order to be very powerful. Some rounds make up for their relatively low muzzle velocities with exceptional expanding bullets. With that understanding, here are some of the most powerful 22 WMR rounds the market has to offer.

Our Picks: Most Powerful 22 WMR Ammo

Self Defense: Hornady Critical Defense 45 Grain FTX

Hornady Critical Defense 22 wmr expanded bullets

This round’s stats don’t look to impressive at first glance: 100 fps muzzle velocity, 100 ft lbs muzzle energy. The important thing to keep in mind is that Hornady recorded these data from a 1.875” test barrel. A shorter barrel gives less time for propellant gasses to transfer their energy to a bullet, which is why a rifle always outperforms a handgun in terms of velocity and energy.

But this round has a trick up its sleeve in the form of Hornady’s FTX bullet. It’s a JHP that is optimized for fast terminal expansion even during low velocity terminal penetration. Hornady also fills its nose cavity with a soft column of polymer. That not only prevents the FTX from losing efficacy as it clogs up with fabric, but also promotes more reliable expansion as it drives inward.

Self Defense: Speer Gold Dot Short Barrel Personal Protection 40 Grain JHP

Speer Gold Dot Short Barrel 22 wmr ammo box

Here we have another self-defense round that appears underwhelming at first glance, but Speer has similarly recorded its 1,050 fps muzzle velocity and 98 ft lbs muzzle energy from a compact handgun’s 2” barrel.

This round owes its potency to its Gold Dot JHP bullet. It features an electrochemically bonded jacket for superior in-flight stability, and which also resists splintering apart to preserve the momentum requisite for deeper penetration. The bullet’s nose cavity is notched. This strategically weakens it to promote more uniform terminal expansion. Again, this is not the fastest or hardest hitting 22 WMR cartridge, but its bullet’s ability to make efficient use of its available power makes it a true force to be reckoned with. (For a 22 WMR, that is.)

Gel Testing 22 WMR Gold Dot Short Barrel Ammo

To test the Gold Dot round’s power and ability as a potential self-defense round, we tested the rounds with ballistic gelatin.

Shooting into ballistic gelatin at the range

We fired from the Federal Bureau of Investigation’s standard of 10-yards away but fired our rounds into bare Clear Ballistics synthetic gelatin. In this test, we used a short, Ruger LCR snub nose revolver with a 1.87″ barrel. (Our hope was to make this as relevant as possible to concealed carriers.)

Our test rounds averaged around 11-inches of penetration. The FBI prefers rounds that travel a bit farther into a target. Especially in our scenario where there was no barrier — we would ideally like to see the bullet reach farther into the target.

Expanded Gold Dot bullet in ballistic gelatin
The Gold Dot Short Barrel did give us some expansion, as you can see in the photo above. We observed an average of .32-inches.  Not bad, but not necessarily impressive either when you consider that’s about half what a good 9mm round will penetrate.

We felt like this provided a good takeaway and lesson: 22 Mag ammo can be effective but no matter how good your ammo, you likely would be better off with a larger caliber if you’re relying upon it for self-defense.

Hunting: Hornady Varmint Express 30 Grain V-MAX

Hornady V-Max 22 wmr ammo displayed at a shooting range

Hornady recorded this round’s 2,200 fps muzzle velocity and 322 ft lbs muzzle energy from a 24” test barrel, so it gives you a much better idea of the 22 WMR’s full potential. This round’s lightweight and ballistically efficient V-MAX bullet is capable of retaining 134 ft lbs of energy at 100 yards, which is enough to make short work of any rodent.

The V-MAX’s sharp polymer tip is positioned over a deep cavity in its core. It builds up substantial energy before connecting with the base of the core, at which point it triggers lightning-fast fragmentation. Although lightweight at 30 grains, here we see a glowing example of how a bullet’s design can contribute so much to its overall power.

Hunting: CCI Maxi-Mag 40 Grain JHP

CCI hasn’t cited the length of the test barrel used to record this round’s 1,875 fps muzzle velocity. Still, that means it enables a rifle to beeline over 150 ft lbs of energy to 100 yards, which just like Hornady’s Varmint Express load is beyond sufficient for hunting small game.

A JHP lacks the performance enhancing features of a polymer tipped bullet, although its basic design has remained unchanged for so many decades because it works. CCI’s bullet consistently penetrates soft flesh until it reaches the depth where a varmint stores its vital organs, expanding all the while so as to register a deadly wound cavity.

Hunting: CCI Gamepoint 45 Grain JSP

This devastating hunting round’s 2,100 fps muzzle velocity lets it transfer over 250 ft lbs of energy at 50 yards or nearly 190 ft lbs at 100 yards. Its jacketed soft point bullet is typically found on larger hunting rounds but it’s no less effective when shrunken down to fit a 22 WMR. The bullet’s tough jacket promotes deep penetration while its exposed lead core deforms to create a wider wound channel than the bullet’s original .224” diameter could ever account for alone.

The Takeaway

So, you have some solid options if you’re looking for powerful 22 mag ammo. However, keep in mind you’re still operating with a round that’s likely half the size of any threat that also has a gun. Shot placement and training as always, remain pivotal if you’re forced to draw your firearm to face that threat.