.22 Magnum Ammunition

Armscor .22 Magnum ammo

Winchester developed this underestimated round in 1959. The concept of the .22 Magnum or .22 WMR—the two terms are interchangeable—comes from Winchester’s .22 WRF round first introduced in 1890. Though the .22 Magnum is a .22 caliber, it is longer and thicker than a .22 Long Rifle round. It also holds more powder and can handle higher pressures. Therefore, the two are not interchangeable. Traditionally, the .22 WMR utilizes a 40-grain jacketed hollow point bullet, but .22 WMR ammunition varies today in that you have your pick from a wide variety of varmint, hunting, and plinking rounds.

.22 WMR is a rimfire cartridge, which means the primer is in the rim of the cartridge. The firing pin hits the rim of the cartridge to ignite the bullet.

S&W 51
S&W 51
The .22 Magnum is an effective small game and varmint round. Knock-down power for varmints is good up to 125 yards and 50 yards for small game. With the right bullet, distance, and shot placement, a .22 Magnum can even take down a coyote. Because the .22 Magnum can hold more power, velocities reach up to 2,000 feet per second from a rifle and 1,550 from a handgun.

Though Winchester developed the round, it was Ruger and Smith & Wesson that first had guns to shoot it. Both initial guns were revolvers, and later Savage made a rifle for the .22 WMR called the Model 24. Winchester also produced the Model 61. In 1977, H&R made the first semi-automatic rifle chambered for the .22 Magnum. There was even a machine gun chambered for it, the EDDA. Today there is a large choice for .22 Magnum revolvers and bolt-action rifles, but very few semi-automatic rifles and handguns. The latest to enter the market is the semi-automatic Kel-Tec PMR-30 handgun.

Great groups with the Armscor .22 Magnum
Great groups with the Armscor .22 Magnum
As far as performance goes, the .22 Magnum is good for prairie dogs, ground hogs, squirrels, snakes, rabbit, turkey, and other small varmints. If you are going to hunt edible game with a .22 Magnum, shot placement is of the utmost importance. As the most powerful rimfire cartridge available, it has the ability to blow away small game and destroy the meat. This is especially true when hunting rabbit or squirrel. Without getting into a discussion about the knock-down power of self-defense rounds, Marshall and Sanow give the .22 WMR a 42% rating in one shot to stop a two-legged threat. This is a better rating than the .22 LR and the .25 ACP. For self-defense, experts recommend a jacketed hollow point bullet, because the hollow cavity in the bullet allows for expansion when it hits mass. Hornady’s self-defense round, the Critical Defense 45-grain FTX bullet is comparable to the .380 ACP in terminal ballistics. North American Arms produces quite a few choices of their Mini Revolvers and the Pug in .22 Magnum. The NAA revolvers are highly concealable, a true pocket gun perfect for back up self-defense.

When I was researching this surprisingly powerful load, I found that many people have no confidence in its accuracy, however the .22 Magnum is excellent in maintaining its trajectory and produces less than 1-inch groups at decent distances.

I tested Armscor 40-grain jacketed hollow point rounds in a 1960 S&W Model 51 revolver with a 3-1/2-inch barrel. Armscor makes their ammunition in the United States and each round is polished and consistent. The ammo boosts the muzzle velocity to about 1875 feet per second. I like Armscor because if you find one faulty round in your box, they will replace the whole box free. Armscor is also one of the most affordable brands that Cheaper Than Dirt carries. In price, it competes with Fiocchi. This makes sense because Armscor makes ammunition for Fiocchi. That is why you will find the F headstamp on Armscor .22 Magnum ammunition.

Armscor .22 Magnum ammo
Armscor .22 Magnum ammo
Even though I did have one failure to fire in the first rotation through my cylinder, I put it through again and had no problems. The long trigger pull on my S&W takes a few rounds to get used to, but once you have a feel for it, shots are accurate with no flyers. The recoil on the .22 WMR is minimal, which means you get better groups. I read that .22 Magnum performs better in revolvers than in rifles, but I have not had a chance to test the theory.

The .22 Magnum does fall short at long ranges, as does any rimfire cartridge. For optimum performance, shoot the .22 Magnum at no further than 125 yards. Due to their size, any .22 caliber round can handle only so much pressure before the load becomes dangerous. Regardless, the .22 Magnum is more powerful than any other rimfire caliber.

For versatility, price, and accurate performance, the .22 WMR is one of my favorite rounds.

The Mission of Cheaper Than Dirt!'s blog, The Shooter's Log, is to provide information—not opinions—to our customers and the shooting community. We want you, our readers, to be able to make informed decisions. The information provided here does not represent the views of Cheaper Than Dirt!

Comments (16)

    1. I am trying to find amanision for my ME 38 Magnum -5.5D cal .22 (5.5 mm) can you tell me what I need and point me in the right direction please

  1. I recently got a Keltec PMR30… and in the case is a slip that says that the Armscorp 40gr is not recommended for it… do you have any experience with it???


  2. Fantastic article and comments. FYI–the Kodiak Model 260 was the first .22 magnum semi-auto rifle ever produced. It was manufactured by the short-lived (1963-1966) Kodiak Company of North Haven, Ct. Kodiak was located in North Haven Conn. They were in business for a relatively short period of time, circa 1960’s. Besides 22 rifles they made other long guns, ( centerfire rifles & shotguns ), in small quantities. There is some speculation that they had a connection with Colt, and some of Colt’s longarms of that period were there products. If you google the Colteer 22lr you will see it resembles the Kodiak.

  3. I’d like to know your thoughts about using .22 WMR shot rounds. I have used them when hunting in my revolver as a snake round and I feel it works very well. Your thoughts?

  4. Great article–one of the best I have read on this site. This is a wonderful round, and contrary to the commentary by the big bullet crowd, the 22 mag excels in self defense as well. One of the biggest problems that we see in this round for revolvers is the fact that it appears most manufacturers make their 22 lr and 22 mags from center fire guns. For example, with the Smith and Wesson, they use the same barrel diameter for their 22s that they use for their 38 and 357 calibers and merely bore the barrel to a .223 diameter. Consequently the guns become inordinately heavy for the amount of power it carries. You can get a lighter gun in a Smith & Wesson Kit Gun, but they are pricey. My point is that the public would be more receptive to these handguns if they were lighter making it easier to carry while backpacking and roaming the back woods.
    It is also the preferred round for those involved in survival. Consider the fact you can carry 500 rounds of 22 magnum along with a 5 1/2 pound rifle for considerably less weight than carrying a 223 rifle and 20 rounds. For survivalists, women and children–and anyone else that likes to pack light, this is the most sensible round along with the rounds lightweight rifles.
    When I carry a 22 mag, I rarely feel undergunned.

  5. My favorite my Marlin 783. It’s very old and still very accurate.Mosty always used CCI ammo.

  6. I have .22 magnum in Winchester 250 lever action, 275 pump action, 2 Mossberg Chuckster bolt actions (in early and late versions) a Tanfolgio revolver, a Ruger convertible revolver and a Keltec PMR 30 (WWII machine gun twin roller action; brilliant and perfect) . They are all tack drivers and outshoot other calibers in accuracy, low recoil and power. The pistol self defense ammo by Hornady, Speer and Winchester are extraordinary. I wish I could get a Keltec PMR 30 in a carry size.

  7. Would it be possible for you to show an image of the “F” headstamp that you describe? I am curious if it looks the same as teh Fiocchi “F” that I have seen on .22 LR cartridges, or if it is a bit different.

    Thank you kindly,


  8. I own a Savage Model 24 and second to me 8mm Mouser, it’s one of my favorite rifles to shoot. The rifle is extremely accurate at 100 yards and I can pop orange clay targets propped up at that range all day long.

Your email address will not be published. Required fields are marked *

Time limit exceeded. Please click the reload button and complete the captcha once again.

Your discussions, feedback and comments are welcome here as long as they are relevant and insightful. Please be respectful of others. We reserve the right to edit as appropriate, delete profane, harassing, abusive and spam comments or posts, and block repeat offenders. All comments are held for moderation and will appear after approval.