- Airgun accuracy. What should you expect from today's airguns?
Airgun accuracy. What should you expect from today's airguns?
By Tom Gaylord
exclusively for PyramydAir.com. © Copyright 2004 All Rights Reserved
Accuracy is always subjective. One person shoots at a tin can 20 feet away and another wants to hit an aspirin at 50 yards. Both consider their guns to be accurate if they can hit their target. Still other shooters want to see what an air rifle will do at 100 yards, while hunters usually just want a clean killing shot on their quarry. In this article, we will discover what you can expect from several types and even some specific models of airguns.
Russia's IZH 46 is a 10-meter target pistol capable of world-class accuracy. Here, not one but five pellets have sailed through the 10-ring. Such a pistol groups top-quality target pellets in five one-hundredths of an inch or less at 10 meters.
Every product has specifications that limit performance. The barrel, powerplant and pellet are at the heart of every airgun's accuracy. Other factors such as how controllable the trigger is and how well the stock fits the shooter are also important, but the barrel and pellet comprise about 90 percent of the accuracy potential for an airgun.
The powerplant adds a small amount of additional potential, but that may become increasingly important with some kinds of powerplants if the shooter does not practice proper shooting techniques. Some powerplants, like those using compressed air, are very forgiving while others, namely spring guns, are not.
A scope sight will make it easier to shoot any airgun more accurately, but it will not make the gun more accurate. Use a scope if it helps you shoot the gun the way you want to shoot, such as for long-range precision shooting and hunting, but also consider if other kinds of sights might even work better for what you are trying to do. For example, a red dot sight allows much faster target acquisition than a scope, but it isn't as precise. If you don't need that last half-inch of accuracy, it could be a good choice.
How to measure a shot group If we're going to talk about accuracy, we have to use some easily understood means of comparing relative shot placement. Shot-group size is by far the most popular way to do this. Incidentally, the term "group" is correct; it is not a pattern. A pattern is the spread of shot from a shotgun; a group is the arrangement of shots from a gun that shoots just one projectile with each shot.
Measuring a shot group is not hard, but there are some things you need to know. The most common way of stating the size of a shot group is the distance between the centers of the two shots farthest apart. This is often shortened to the expression "center-to-center," or "c-t-c."
Measure a group by measuring the distance from the far edges of the two widest shots, and then subtract one bullet diameter to get the distance between the centers. If the two widest shots of a group of .22-caliber shots measures 1.220" across their widest distance, the c-t-c distance is 1.0". The math is simple, and it works the same for all groups and all calibers.
When you measure the group spread, don't forget that most bullets except wadcutters will tear raggedly through paper instead of cutting a clean hole. You need to find the true edge of the two widest holes. In the beginning it helps to stick a pellet in the holes to visualize where the edges are. With some experience, it becomes easier to estimate where the edges are and you won't have to use a pellet.
It's easy to measure groups with a plain old ruler. Simply bracket the outsides of the two widest shots. Here, a Condor from AirForce
puts five .22-caliber Korean pellets into a group that measures a hair larger than 1-1/2" at 50 yards. Subtract the 0.22 diameter of one pellet and you get a group size of just over 1.28". Not bad for a breezy day in Texas! Don't expect your .22 rimfire rifle to shoot this well unless it has a great pedigree. The Condor will shoot groups half this size on calm days. The edges of the pellet holes are difficult to see in this photo but are more obvious when you have the target in hand.
Dial calipers make it easy to rapidly measure group size. Don't be fooled by the precision of the reading, though. You'll be fortunate to measure correctly to within a hundredth of an inch. This group of five .50-caliber airgun bullets was fired at 25 yards from a Dragon big-bore air rifle
. It measures just 0.816", center-to-center.
You can measure the distance across the group with a common ruler marked in sixteenths of an inch or you can use a dial caliper that indicates thousandths of an inch. Whatever you choose, don't kid yourself that a more precise measuring tool will make your measurements more accurate. This is a common mistake. Simply because you are measuring in thousandths doesn't mean you are doing it accurately. It just makes the results sound more impressive, such as a 0.125" group, compared to a 1/8" group.
What accuracy is possible with an airgun? Obviously, groups shot closer will be smaller than those shot farther away, given the same circumstances. With an Olympic-grade 10-meter rifle like the Walther Alutek or a target air pistol like the Aeron B98, five-shot groups measuring only a few HUNDREDTHS of an inch in width are possible. That's at 10 meters, which is about 33 feet. With a sporting rifle such as the Webley Longbow, a group size of one-tenth of an inch is possible, if the shooter uses the correct technique. Use a sloppy technique and you can easily see a half-inch group from the same gun at the same distance. Some of the top sporting rifles like the BSA Super 10 MK II will give even smaller groups at this distance, rivaling the target guns.
At the same 10-meter distance, a nice sporter air pistol like the Webley Tempest or Weihrauch HW 75M will group five shots in one-tenth of an inch. A high-quality CO2 pistol like a Smith & Wesson 586 might group five shots in three-quarters of an inch and a low-cost CO2 gun like a Gamo P23 might shoot a 1-1/2" to 2" group. A lower-cost rifle like a Crosman 1077 might shoot a quarter-inch group at this distance, while a Benjamin Sheridan single-shot pneumatic might group in one-eighth of an inch.
As the range increases, so does the group size for all airguns. At 50 yards, a 10-meter target rifle will be shooting a group of three-quarters of an inch to one inch, while a top-quality sporting rifle like the AirForce Talon SS can shoot a half-inch group. Air pistols are pretty much out of the picture beyond 30 yards or so, but they can be fun to shoot at the longer distances if you like a real shooting challenge.
You may read discussions about half-inch groups at 50 yards and they may sound easy, but they're not. A half-inch five-shot group at 50 yards with an air rifle is the shooting equivalent of a par hole in golf or a bowling score of greater than 240. Everyone loves to talk about such things, but they are not as common as you might believe.
If 50-yard five-shot groups of one-half inch are possible, it stands to reason that there will be even better groups from time to time. Indeed, quarter-inch groups at 50 yards are not unknown. They happen with the same frequency as holes-in-one in golf or 300 scores in bowling.
At 35 yards, a Talon SS from AirForce
shot this five-shot group of .22-caliber pellets. And, some folks say .22 caliber isn't accurate! My wedding ring is size 12.
When the distance is stretched to 100 yards, the bragging group size is one inch. And, such groups have been shot, but they are even more rare than half-inch groups at 50 yards. The longer a pellet takes to fly to its target the more wind will influence it. I would rate a one-inch 100-yard group as four times more difficult to shoot than a half-inch 50-yard group.
The number of shots in a group affects the size There's a secret to shooting small groups. Simply shoot fewer shots. A three-shot group looks pretty convincing, and it is 60 percent easier to shoot than a five-shot group of the same size. A two-shot group is even easier and some shooters are so eager for bragging rights that they will settle for two close shots. Nobody has tried to put a one-shot group up for scrutiny yet, but it wouldn't surprise me if someone did.
On the other hand, a 10-shot group will be about 40 percent larger than a five-shot group from the same gun. Whenever the accuracy of a gun is being measured, 10-shot groups are considered the standard measurement tool, though few shooters, including yours truly, ever invest the time and effort to shoot them.
When the only person you have to please is yourself, shoot whatever number of shots you want, but a test report with groups of less than five shots is suspect, to say the least. I have recently shot some 10-shot groups at 50 yards with a Ruger 10/22 rifle I'm testing. Eight of the 10 shots went into a group measuring 1-1/2", but shots nine and 10 opened up that group to 8-1/2"! That's an extreme example of what I'm illustrating, but I never got a 10-shot group of less than 2-1/2" with that ammunition in that rifle, so what does that say about the 1-1/2" eight-shot group?
Settling down to shoot You have to settle down to shoot good groups. The hyperactive shooter has no chance of shooting as accurately as the shooter with proper technique. Not only does your breathing and heart rate come into play; your mental frame of mind is essential to accuracy. I like to use a line from the movie "Patriot." When Mel Gibson was telling his sons how to hit their mark, he said, "Aim small, miss small." Whoever made up that expression knew what it takes to shoot accurately.
On Army pistol ranges, I have seen soldiers deliberately aim at a target 50 feet away and hit the ground 15 feet in front of where they were standing. All because of improper trigger control. I have also seen a national champion shooter, my squadron commander, take the same tired Army .45 and shoot a 2" 10-shot group at the same distance. You have to settle down and use the proper technique, or you'll never get all the accuracy your gun has to offer.
The group sizes mentioned and shown in this article are very achievable with a good airgun, good pellets and a good shooter. One good reason to shoot airguns is that they give you the best shooting training money can buy. When you move back to the more forgiving firearms, your time spent with an airgun will have sharpened your skills.