Common Rimfire types

 

Common Rimfire Calibres

1. .22Short ( although slowly dissapearing from demand / production ),
2. .22LR ( Long Rifle ),
3. .22 LR Hyper Velocity ( Specially for Vermin Control / Hunting ),
4. .17HM2 ( Hornady Mach 2 )
5. .17HMR ( Hornady Magnum Rimfire )
6. .22WMR ( Winchester Magnum Rimfire - sometimes called .22 Magnum),

Of the above 5 ammunition types, - .22LR,  .22LR Hyper Velocity, .22WMR and .17HMR are the most commonly used

.22 Short Round

The .22 Short was really produced as the round for defencive purpose serving mostly in Revolvers - it is still available today but you are most likely to only find one or two options in your local gun shop compared to the various brands and types available for the .22 LR
Note: Firing .22Short in some .22LR firearms will result in keyholing due to difference in the barrel twist required for the rifles compared with .22Short firearms.

.22LR Round

The .22 LR is the most common rimfire round and is a great introductory firearm for beginner shooters, most people will have shot a .22 for their first 'real gun' and it would most likely have been a Bolt Action rifle but in other cultures such as in the United States firearm ownership is a proudly followed tradition and right, there are many different types and it is highly likely most people may have fired a semi automatic such as the well known Ruger 10/22, but other brands have entered the market and most recently notably being Remington with their 597 model and Mossberg with it's 702 'Plinkster' model. In the United Kingdom it is much more common to find Bolt Action rifles amongst shooters due to tradition as well as the truly over strict firearms laws, although semi automatics in .22LR are legal, people generally shy away from them as they fear the government's possible next steps into further gun control ... hence Bolt Actions are highly common with a few lever actions here and there.

.22WMR Round

.22WMR also known as .22Magnum was designed with power vermin hunting in mind to bridge the gap between something too powerful such as .223 ( 5.56mm in Military Terms ) and the weaker .22LR, hence why the round has a longer casing which contains a lot more propellant and the bullet itself having a copper jacket normally with an expanding hollowpoint tip.

.17HMR Round

The .17HMR is the one of latest rimfire rounds which was invented in 2002 by Hornady ( Hornady Magnum Rimfire ) with vermin hunting / control being their design purpose - the round has an extremely impressive velocity of an average 2,350 - 2,550 fps (Feet Per Second - the muzzle velocity) it has an extremely good flat trajectory but the bullets are susceptible to windage due to their relatively small weight (+- 17 grains - 20 grains depending on the round type) compared to the .22LR which is great in wind but is affected by trajectory due to the heavier weight of 40grains in normal .22 Ammunition.

.17HM2 Round

 .17HM2 is the smaller brother of the .17HMR round and was developed not only to be an alternative to the new HMR round but to be that High power option for individuals who need higher power but still prefer the size of .22LR ammunition  - it is much smaller but still extremely similar in design and shape - the HM2 is not so much a popular round and has pretty much failed to make an impact in the international shooting scene - thus the .17HMR looks to be the market dominator in powerful Rimfire shooting and vermin control
One advantage of the .17HM2 is that it is a similar size to the .22LR and advanageously the rounds fit and work in the Ruger 10/22 Rotating magazines as seen below;

.17HM2 Rounds work in Ruger 10/22 Magazines



.22LR Shotshell rounds / Rat Shot / Snake Shot - plastic capsule form

.22LR Shotshell, also known as Rat Shot or Snake Shot - is basically the same concept as a shotgun cartridge whereby instead of a solid bullet being fired, it is shot or pellets designed primarily for pest control


 

.22WMR Shotshell round in plastic capsule form

.22LR Shotshell round in crimped case form

 

The speed groups (velocities) of .22LR Ammunition:

• SUBSONIC: Speeds below 1,100 ft/s or 340 m/s,
• STANDARD VELOCITY: 1,000 - 1,135 ft/s or 300 - 346m/s,
• HIGH VELOCITY: 1,200 - 1,310 ft/s or 370 - 400 m/s,
• HYPER VELOCITY: Over 1,400 ft/s or 430 m/s.