My
previous post dealt with the most common kinds of .22 ammunition. In this post, we'll look at some of the less common types.
Target or match ammunition:
Target or Match ammunition is more or less identical to standard velocity ammunition in overall performance. It's characterized by a 40 grain round nosed projectile, and velocities that are subsonic- around 1080 fps. There are several reason for this. First, a supersonic projectile generates much more atmospheric drag than does a subsonic projectile. Second, when a bullet is traveling faster than sound, it's dragging a shock wave behind it. As the bullet decelerates, the shock wave catches up with the bullet and overtakes it- disturbing its flight. Third, there's no need for high speed. Target ammunition doesn't need any more energy than it takes to get downrange and punch through a piece of paper. The flatter trajectory that comes with high speed is unimportant when you're only shooting at known ranges.
There are a number variables that can affect accuracy in .22 ammunition. The powder charge must be absolutely identical from round to round. Projectiles must be perfectly symmetrical about their longitudinal axis, and be identical in weight. (Eley laser scans every single Tenex bullet before loading it!) Primer charge must be absolutely identical from round to round. This calls for careful control of the manufacturing process and measuring each round for weight and dimensional consistency.
Rim thickness is also carefully controlled in the best target ammunition. A slightly thicker or thinner rim will result in a change in ignition, and that can influence the trajectory of the bullet. Many target rounds also use special lubricants. For example, most manufacturers use paraffin as a .22 bullet lubricant, as it's inexpensive, it works well, it's hard, won't wipe off, and it doesn't break down over time. Eley uses paraffin on their least expensive .22s, but on Tenex and other higher priced ammunition they use a mix of beeswax and tallow. This is a compound with improved lubricity over paraffin that gives better results but has to be handled a bit more carefully, it's more expensive, and over time it will dry and crumble.
All this results in significantly higher cost than standard ammunition. The cheapest target ammunition, like Eley Club and Aguila Match, runs $3 to $4 for a box of 50. CCI Green Label, which I have been told is selected from runs of their Standard Velocity, is typically $7.50-$8 per 50, or over twice as much as the standard velocity. The best ammunition used by National and Olympic competitors, like Eley Tenex and Lapua X-Act, can run $20-30 for 50 rounds.
To get the most out of real target ammunition you need a gun with a match chamber. Most guns have a chamber made to the SAAMI "sporting" chamber dimensions. They're a bit looser than match chambers in order in insure smooth cycling with a range of ammunition, even after many rounds have been fired and the chamber is a bit dirty. Match chambers, as found in single shot pistols and rifles, are much tighter, in order to insure consistent shot-to-shot performance. Auto target pistols often have a chamber with dimensions somewhere in the middle, to insure reliable cycling while maintaining good accuracy.
Low powered .22LR cartridges
Next up are the various low lower rounds designed for plinking, indoor target shooting, or dispatching small pests. Standard ammunition typically has a muzzle energy of around 100-120 foot-pounds when fired from a rifle barrel. These round run anywhere from a high of 40 foot-pounds down to a low of only 6 foot pounds.
One popular low-powered round is the CCI "CB Long," which resembles the old .22 Long cartridge, but has a much smaller powder charge. Muzzle energy is 30 foot-pounds, which is similar to what a high-powered .22 air rifle would generate. Remington has the "CBee" which propels a 32 grain hollow point with 40 foot-pounds of energy. Used in a rifle, these cartridges have a mild sound report that's more like a cap gun than a .22.
Aguila makes two low powered rounds, one for pistols and one for rifles. The rifle version is called the Super Colibri and has a 20 grain bullet that leaves the barrel at 500fps, resulting in a muzzle energy of only 11 foot-pounds. This energy level is close to the typical spring-piston air rifle. The pistol version, called simply the Colibri, generates only 6 foot pounds of energy- close to what a spring piston air pistol would generate. I've fired these in a rifle, but I'm told in some rifles there's a good chance they'll only make it part way down the barrel! Both of these rounds can be safely fired indoors (assuming you have a solid trap and backstop and if local laws allow) without annoying the neighbors, but you need good ventilation, as the primers contain lead. (In fact, just about all the airborne lead found in indoor ranges comes from the primers.)
Next up:
Subsonic rounds.
Most standard velocity .22 LR cartridges are subsonic, or very close to subsonic, which might make you wonder why there are also cartridges that are labeled "subsonic" as well. It's probably due to the explosion in interest in suppressed .22 pistols and rifles. You can't have a silenced round if it makes a supersonic crack as it passes by. Just about everything said about standard velocity rounds is also true of subsonic rounds. Projectiles are typically round-nosed 40 grain bullets, and velocity is just under 1100 fps.
There is, however, one subsonic round that's very different from most on the market. It's the Aguila SSS Sniper round
I've written about previously:
Aguila manages to get 120 foot-pounds of muzzle energy out of a cartridges generating only 950fps of muzzle velocity via the use of an extra-heavy 60 grain bullet. As you can see, the bullet is quite a bit longer than the typical 40 grain bullet. Aguila managed to keep overall cartridge length within spec by using a .22 Short sized case. I've found that these will cycle most semi-automatic .22 pistols and rifles I've tried them in. It's a very clever design, but it does have a downside- poor accuracy in most guns. The problem stems from the fact that the longer a projectile is, the faster it has to be spun in order to stabilize it. The round balls used in early muzzle loaders got by with rifling twists of 1 turn in 48"; a modern .22 rifle typically has a twist of 1 turn in 16". The Aguila SSS is said to need a twist of 1 turn in 9" to fully stabilize. If your gun has a faster than usual twist, these are great for short-range small game hunting, as they deliver a lot of energy without too loud a report.
.22 Shotshells
New shooters might be very surprised to learn that there are indeed .22 caliber shotshells. Most are of the crimped construction, in which a longer than usual case is filled with powder, a tiny under-shot wad, and 25 grains of #12 shot, and then crimped closed, like these Federal Game-Shok cartridges:
CCI makes a different sort of shell that uses a standard .22LR case and a plastic shot capsule that can hold slightly more shot- 31 grains, to be precise:
#12 shot, being only .05" in diameter, has an exceptionally low sectional density, and consequently loses muzzle energy very quickly. It's useful for things like shooting pigeons or other similarly sized vermin in a barn without putting holes in the roof. You can also fire it up without worrying where the projectiles will fall. Some hunters use them on squirrels and rabbits at very close range, but that's probably pushing it. Biologists have been known to use them for collecting specimens, much as James Audubon collected the bird specimens he painted via the use of a small gauge shotgun filled with was then called "dust shot."
.22 shotshells are two or three times as expensive as standard velocity rounds, so few buy them unless they have a specific use in mind. The Federals are typically $8-9 per box of 50, and the CCIs, $9 per box of 20.
Miscellaneous types
Ammunition makers have been producing more and more specialized rounds to cater to tastes, and no doubt for marketing reasons as well. CCI, who seem to have more specialized .22LR than anyone else, has "AR Tactical Rimfire Ammunition" which is said to be especially for "AR Style arms," and that it was tested specifically for the S&W M&P15-22. Winchester has the similar M22, designed for "high volume" shooters, i.e., plinker with AR-style guns. Whether these, or any other specialized round is actually functionally different from one of the more standard rounds is anyone's guess.
So what kind of .22LR ammunition should I buy?
For plinking, the bulk-pack stuff is the way to go for economy. For shooting at steel plates at 25 yards, it's probably even competitive.
Casual target shooting at paper targets, use bulk pack or standard velocity or the lower priced target rounds, like Aguila. Experiment and find out what's most accurate in your gun. If you're seriously interested in bullseye competition, your fellow competitors will suggest to you what works in your gun.
Hunting smaller animals at close ranges, use the subsonic or standard velocity to keep the noise down and get better accuracy. Out to 50 yards, or on tougher small game, use the high velocity hollow points, or even the hypervelocity stuff.
No doubt over time you'll develop your own preferences. Then you can come back, read this blog, and say to yourself, "he has no idea what he's talking about!" ;-)