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Is airgun barrel length important?

By B.B. Pelletier

Here is a subject that gets people riled – quick! Is barrel length important in an airgun? Yes, it is, but the reasons may be different than you think.

Barrel length DOES NOT determine accuracy
There is NO CORRELATION between barrel length and accuracy. A short barrel can be more accurate than a long barrel, or vice-versa. Length alone has nothing to do with it.

Pellet control is not the issue
The people who think longer barrels are more accurate often say it’s due to the greater control the longer barrel exercises over the pellet. A barrel does not “control” a pellet in the same sense that a dog trainer controls a dog. Once the pellet leaves the muzzle, it doesn’t matter whether it has been in the barrel for 10 inches or 30; it is now a ballistic missile and subject to the same physical laws.

Proof that short barrels are just as accurate
A target air pistol such as the Aeron B99, which has an eight-inch barrel, is just as accurate as a target air rifle – like the TAU Senior – D, which has a barrel approximately twice as long. You can see this in the test targets shipped with the guns.

AirForce Airguns states that their Talon SS with a 12-inch barrel can shoot one-inch groups at 50 yards. They say the same for their 24-inch barreled Condor. Once again, this is from actual testing on real airguns.

Barrel length does influence velocity
Both pneumatic (all types) and gas-powered guns gain velocity with longer barrels. The expanding gas (or air) has more time to push on the pellet in a longer barrel. There is a limit to this, of course, but you aren’t likely to ever see an airgun barrel long enough to reach it.

Cardew determined optimum spring gun barrel length
A spring gun gets all of its “push” in the first few inches of the barrel. Gerald Cardew pointed out in The Airgun from Trigger to Target that only the first six inches of the barrel is needed for a spring gun to achieve maximum velocity. His experiments were conducted in the mid-1970s. Although technology has advanced since then, today’s spring-piston guns probably don’t use more than the first 10 inches of barrel for top velocity.

After that, the pellet coasts the rest of the way. Yes, friction with the bore slows the pellet somewhat, but the amount is so small that it doesn’t amount to anything. Spring gun barrels are made longer than 10 inches because they are used as levers, as in breakbarrels. And, on all rifles, a shorter barrel just doesn’t look right. That’s why the underlever TX 200 from Air Arms hides its nine-inch barrel inside a longer shroud that also muffles the sound of the shot.

I will address the important contributors to accuracy in future posts. I think we all would like to know more about the subject. I will also suggest some tests that you can conduct on your own to determine the best accuracy for your airguns. It will take several posts to get it all, so there is something to look forward to.

So, airgun barrel length is a factor in performance, but accuracy is not directly affected. Some people may still not believe this, but all the literature I have read and all the tests I have done show it to be true. Any thoughts?

28 thoughts on “Is airgun barrel length important?”

  1. In that barrel length may be a determining factor of sight radius, wouldn’t it be important to accuracy?
    Yeah, I know, even the pros go round and round about the importance of sight radius to accuracy, but it is arguable that a longer sight radius reduces faults on the target resulting from normal sight deviation.

  2. BB- You are right. Some time ago l removed 4.5″ of a (scoped) Gamo Shadow barrel. l wanted a more compact woods rifle. Anyway it has not lost any speed or accuracy, thank god, because it never was much better than a 1″ at 25 yard rifle. By the way l get several thousands of a inch scope base movement with each shot, even with there scope stop, any advice-Thanks

  3. B.B.

    Did you ever write an article and talks about how to make an accurate airgun barrel or what makes an airgun barrel accurate ?

    I cannot find such article.


  4. Joe,

    I did a report about rifling, which concentrated on how it is done. But I doubt I’ve written an article about making an accurate airgun barrel or what makes a barrel accurate.

    While I do know some things that we all like to see in barrels, I’m not sure they constitute everything that makes a barrel accurate.

    I know a little more about firearm barrels, only because more has been written about them. But I’m no expert. Maybe a person who can conduct a conversation for a while.


  5. Hi bb just bought a s/h theoben fenman now i was concerned about the accuracy of its very short barrel(about 8″) but i found out this rifle is able to produce half inch groups at 40 yards @ 12ftlb its been a while since i have shot air guns so with practice i hope to achive this with the help of your advice and plenty of practice and what a lovely gun far more rewarding than precharge.

  6. B.B.,

    For springers doesn’t a barrel longer than 10 inches decrease accuracy?

    The extra length would seem just to give the barrel more time to move around due to recoil. It seems springer barrels should be designed to get pellet flying in 10 inches and them have a shroud to be the lever.

    Can’t hep but wonder how well a TX200 would do with a full length barrel.


  7. Does this same principal apply to big boars?
    Would a barrel extension on a .50 Dragon slayer increase velocity on a 275 grain bullet?
    If so then WHERE CAN I FIND an extender for the Dragon Slayer??

  8. Physics is the same for all guns, regardless of the caliber. Yes, a longer barrel does add velocity to a big bore.

    There is no such thing as a barrel extension. You need a new, longer barrel and it will probably cost as much as the gun, since it will have to be custom-made.

    If you are still interested in this topic, I can write a special blog report about it for you. I am in New York filming a television show through Friday, Sep. 11. If you will contact me on the current blog after that, I will write the report.



  9. my belief that longer barrels have more accuracy has nothing to do with control. its just because of bullet drop or wind or things that can change the direction of the bullet.
    so because its faster, it doesnt have time to drop much. i know im still amateur but thats what i thought

  10. There are two very similar Norica air rifles: Storm and Black Eagle, both with the same power, around 23 joules, the same speed but with two different barrel length (454 cm the first one and 354 the second one). Why this difference? How it may affect the performance (accuracy, etc.)?

  11. dietamediterranea,

    As you see, barrel length is a springer is relatively unimportant. It stops affecting velocity after nine inches, or so. The only things it does affect are the distance between the front a rear sight and, on breakbarrels, the length of the cocking lever.


  12. Mr B.B
    you said: "A target air pistol such as the Aeron B99, which has an eight-inch barrel, is just as accurate as a target air rifle – like the TAU Senior – D, which has a barrel approximately twice as long. "

    can you proof with scientific reasons?


  13. You miss-read what I said. I said the rifle barrel is just as accurate as the pistol barrel.

    But why would you think that a short barrel is less or more accurate than a longer opne? Everything we know about barrels disproves that.


  14. I turned a 22 cal stevens barrel down to fit a beeman air rifle. Barrel length is 227/8 in. long .at 40 yards it will cut the same hole 5 out of 5. before I did this the best was a 2 in group .FPS did not change but the flight did.So I believe the twist and length, plus barrel steel does make a differance

      Great to see I’m not the only one with this idea. I’ve got a Ruger 10/22 barrel that I’m not using anymore(upgrading to a bull barrel) and a Crosman MTR77 that I’m gonna put it in. I know, I know, I’m putting a ball gown on a hog but still, they don’t offer the crosman in .22. So bein’ a true Yankee engineer I figured I’d do with what I have.
      Couple of questions though; Did you thread thread the receiver side or is it interference fit? Did you bother turning the whole length or did you leave the nice contour that the Stevens already had? Seems like it would be waste of movement dampening weight to turn away all that metal.

      • Your 10/22 barrel will not likely shoot 22 cal pellets well as 22 lr is actually .224 and airgun pellets are .219. You will be better off using light 22lr bullets, 36gr or lighter if there are any much lighter. Unfortunately ive thought about using 22 powder bullets in air rifle barrels but 22 hornet etc are .204 and 22 long, magnum, etc are 224. A 20 cal magnum velocity air rifle might send hornet bullets well, for the uk crowd (never seen a 20 in the us personally, not well distributed here.) On the other note, cutting a barrel can produce leaps in accuracy because of, get this, the crown. Nobody mentioned it. Recrowning is priority one on a sprayer, powder, air, tennis ball launcher, anything shooting a projectile must loose the item simultaneously from all edges.

    • Johncpen,

      On springers the short answer is yes. Some might benefit from a slightly longer barrel. Some have a short barrel but the outer sleeve is there as a cocking aid. Pneumatics, CO2 and PCPs definitely benefit from a longer barrel.


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