Not to quibble over small details, but I think groups are a measure of precision more than accuracy. Speaking directly to the question, barrel length has no effect whatsoever on accuracy. There are secondary issues related to barrel length that may have influence, such as velocity and wind deflection, or as Brent said, sight radius. ETC, ETC, ad infinitum.

Benchrest shooters proved long ago that shorter barrels are stiffer, more rigid, and produce smaller groups -- all other factors being equal.

AD

What degree of accuracy is enough to matter? I don't think you'll see much practical accuracy difference in a hunting gun other than it may require a different load.

The one exception might be if the twist is wrong for the bullet/velocity combination of the 16" barrel but marginally OK in the longer/higher velocity barrel.

I know how barrel length affects bullet speed but do you lose accuracy as you get shorter as well? How much accuracy do you loose when you go from 22" to 16 1/2"?

You loose sight radius, and that affects accuracy - if you use real sights. Not a factor for glassware however.

Brent

When a bullet first hits the rifling, it is traveling in a straight-ahead direction, and there is no spin. A barrel only has to be long enough to get the bullet spinning at the correct rate in order to be accurate. This statement, of course, is moderated by the need for the barrel to be long enough to properly consume the powder charge.....

For example, a 2" revolver barrel is just as accurate as an 8" revolver barrel, but it is much more difficult to aim precisely with such a short sight radius....

Thanks much for the prompt and great information. This is such a great resource for shoooters!

The advantage of a shorter barrel is fairly simple (assuming everything else being equal, which it seldom is)...



Struck the same blow in the same spot, the shorter barrel will have a higher frequency and lower amplitude of vibration than a longer tube. In simple English that means it will vibrate faster at the muzzle, but the muzzle won't swing as far in each direction.



So, particularly with loads which do not have identical bullet velocities and barrel travel times, although bullets leaving the muzzle after different lengths of times traveling down the barrel WILL still leave with the muzzle pointing in slightly different directions, the amount of that difference is apt to be smaller from short barrels with their lower amplitude of vibration.



There are so many other considerations in finding extreme accuracy, however, that the advantages of a short barrel are usually hidden behind a multitude of other variables.



It is mainly in benchrest competition, where measures are taken to at least try to make uniform ALL the other considerations, that the shorter barrels get to show their stuff clearly.



Alberta Canuck

Allen,

Actually, your comment is incorrect.

Shorter barrels have less mass than longer barrels

Shorter barrels given the same contour as the long barel have the same stiffness as the long barrel.

Rigidity and stiffness are the same.

AC spoke correctly.

Since the shorter barrel has less mass but equivalent stiffness it's (the short barrel that is) first bending mode will occur at a higher frequency, and a lower amplitude, than the first bending mode of the long barrel. The amplitude of the vibraion is termed "barrel whip". With less barrel whip, as AC stated correctly, there is less variation of the actual exit point of the bullet with respect to the target from shot to shot.

There are ways to increase the first bending frequency of a long barrel to achieve the same harmonics as that of a short barrel. Mass dampers are the simplest method, although they have significant limitations. The best method is to increase the dynamic stiffness of the long barrel. This is where fluting comes into play. With that I think I will stop before this post gets WAY TO F_CKING TECHINICAL and I MOST LIKELY LOSE EVERYBODY (except maybe AC as he seems to have a clue )

By the way, AC is refering to AlbertaCanuck, not me.

ASS_CLOWN