What is the optimum length for a 22lr barrel? An age old question and you can probably find as many different answers as the number of people you ask. Just look around in the some of the forums and you’ll see that this statement is very accurate.
One reason for that is the question is not really defined well. What does the word ” “optimum” mean? To some it may mean velocity. To others it may mean accuracy, and no they are not one in the same.
With average standard velocity ammo and 22 lr barrel, you will only get about 14 inches of powder burn per shot. For maximum velocity, the best overall barrel length would be between 14 and 18 inches according to data from tests.
Beyond 14 inches, length of the barrel does not contribute to accuracy.22 lr barrel length vs velocity?
In shooting, our main goal is consistency. There are many variables that can affect the outcome of our shots. Barrel twist rate, ammo consistency, ammo design, trigger pull weight, our ability, the environment, only to name a few.
Through a given 22 lr barrel, most ammo will reach maximum velocity at around the same point – at or around 14 inches. Watch the video below to help clarify this point. Although this is just a small test, data is presented at the end of the video to back up the points made on velocity above.
In this video, although the data size is small, I believe it is representative of what really happens in most barrels. it’s easy to see that maximum velocity is obtained at around 18 inches for this test.
At longer distances velocity starts to decrease as powder burn is finished and barrel friction comes into play. Some people will swear that their old 22 lr rifle that was left to them buy their grandfather will outshoot any rifle produced today because the barrel is 24 inches long. It may shoot better than most rifles but it is not because of the length of the barrel. Most likely, one of the other variables is coming into play.
22 lr barrel length vs accuracy
In my pursuit of long range accuracy I have personally tested many variables in an effort to maximize accuracy, or minimize group size at longer ranges. I can tell you that no test I have ever done has been conclusive in correlating barrel length of a rifle to accuracy. Below is a video that backs this up.
What does 22 lr barrel length affect?
Length definitely affects the harmonics of the barrel. This happens in a couple of ways. The first affect is as the weight increases as barrel length gets longer it changes the muzzle position in relation to the nodes – vibration waves. For more information on this check out this article.
Barrel tuners are believed by some to be ineffective at improving accuracy. The fact is, this is where barrel tuners work. They can be moved up and down the barrel in an effort to try and match the position of the nodes / harmonics in relation to the position of the muzzle.
A longer barrel also adds more weight to the front end of a rifle, which to a point, can have the tendency of stabilizing your hold on a target and somewhat calming shaking muscles. When shooting big bore metallic silhouette matches I would always intentionally weight my rifle in the front for this reason.
All of the shots in this game are taken at ranges out to 500 meters offhanded. Another way a longer barrel could affect accuracy is if it is used to slow bullet speed down to 1000 fps or roughly the speed of sound. When a bullet leaves the muzzle higher than 1000 fps and then passes back through this mark as the bullet slows with distance, turbulence occurs when can negatively impact accuracy.
From an accuracy standpoint. the goal is to keep the bullet above or below 1000 fps throughout it’s entire flight. In certain situations, a longer barrel can serve this purpose.