Thin Is in but Short and Fat Is Where It’s At!

In a previous article for this column entitled “When Size Matters… Snub Nose and Belly Guns” Published on March 7, 2023 I stated: “Due to their shorter barrel lengths, snub nose revolvers are perceived to have less accuracy than firearms with longer barrels. This is not true. Short barrels are in fact intrinsically more accurate. The shorter sight radius, however, does make them more difficult to shoot accurately.” One of the readers, Yorarider, posted this in the comments section:

Great article, but I don’t understand the comment about shorter barrels being “intrinsically more accurate” than longer barrels. No less accurate I agree, but more accurate… you’ll have to explain.

Because of the space required to give the answer it’s due, I decided to devote a column to the answer, so here goes.

Precision

To start with, I must apologize for misstating my position that no doubt lead to Yoraraider’s comment. What I should have said is; “intrinsically more precise.” Precision describes the closeness or the spread of two or more individual shots to each other or how close individual shots are to one another, regardless of the point of impact. Accuracy on the other hand is defined in the shooting sports as, how close a shot is to the desired point of impact or centered on a target, and is determined by how well sighted-in a shooting system is.

If the shot group is not centered on the target, it can be assumed that the firearm just needs to have its point of aim adjusted. That said, it must be understood that there are many aspects of what can influence the precision of a specific barrel, so let me first isolate those aspects and then explain them.

Anyone who shoots often, understands that precision and accuracy are about controlling the variables, and shooting (by its nature) provides loads of variables. We will only examine a barrel’s physical variables in this column and how they might affect its precision. Of the physical variables, we will not only discuss barrel length but also its width or thickness, chambering, contour, powder charge, and projectile to understand my statement.

Because a barrel’s length is what this is about, let me introduce some general beliefs and concepts about barrels. Originally it was believed that longer barrels give the powder charge more time to complete a full burn to propel the bullet. With all else being equal, for that reason it is believed that longer barrels generally provide higher, more consistent, velocities.

However, as the bullet moves down the bore, the gas pressure behind the bullet diminishes. Given a long enough barrel, eventually a point will be reached where friction and air pressure will equal the pressure behind it. At that point, the velocity of the bullet will then start to decrease. This is probably one reason the optimum barrel length for most sporting rifles has been 26 inches for decades, that, and I suppose because it just looks right.

Velocity

It was also believed that for every inch of barrel length that was eliminated that you would lose 25 feet-per-second of velocity. The truth is there isn’t any clear-cut answer as to how much velocity will be lost per inch of barrel reduction, because there are other variables that contribute to the exact amount of lost velocity. Some of those factors include the type and amount of powder, as well as the weight and bearing length of the bullet that play a major part. As a general statement, we do know that rifles in smaller calibers tend to lose less velocity than rifles in larger calibers.

What we can say with certainty is that barrel length influences velocity, which, in combination with bullet design, dictates expansion and penetration. Many also assumed that barrel length and velocity walk hand in hand. However, once again, there are many other variables that must be considered. Some of those factors are, chamber dimension, bore dimension, and the powder burn rate that also play an important role and are important factors in determining velocity.

How barrel length effects velocity is very important, especially when discussing defensive handgun cartridges. You need enough velocity to make the bullet expand and provide sufficient penetration. Basically, relying on someone else’s estimate of how your particular firearms load will perform is tantamount to suicide. A particular load will ONLY generate a certain velocity from a specific barrel. To really know how your firearm is preforming, do yourself a favor and chronograph the specific load you will be using through the actual firearm you will fire it in. Nothing else means anything…

So remember, every load is different, and every firearm is different. Some loads need more barrel length than others to deliver maximum performance, and some firearms because of manufacturing dimensional variations can produce lower or higher-than-expected velocities. The take away of all this has to be that old short hand of 25 fps per inch of barrel length is not as reliable as we once believed and velocity is one of the variables that must be understood and controlled. Now that we have a basic understanding of the roll length plays with a longer barrel, let’s discuss what happens when the barrel is shortened.

Going Shorter

When you squeeze the trigger, you are initiating what amounts to a controlled explosion that launches a projectile. That explosion creates osculations that affect the entire system. As the shooter, you must understand and find ways to deal with this vibration and turn it into an advantage because taming barrel harmonics is what precision is all about. Understand, all barrels oscillate when bullets travel through them…. Even .22 Rimfire firearms. 

The amount of whipping a barrel displays is proportional to the length and thickness of that barrel, and so it is that barrel length and contour determines the relative “stiffness” of a barrel, i.e., how much a barrel will tend to whip or vibrate. Barrel stiffness helps reduce harmonic issues and generally a thicker, stiffer barrel will be more precise. A heavier contour also tends to provide less variation between a cold shot and subsequent follow-up shots as the barrel heats.

Barrels also tend to expand as they heat up and as the barrel expands any stress on or in the barrel will cause stringing of the shots resulting in an increase in the group size. That is why heavier barrels also tend to be more consistent, because they take longer to heat up and heat is a major factor. Rapid strings of fire such as those found in a prairie dog town heats up the steel making the barrel more pliable, and that causes it to expand. Do you have a barrel that walks its shots as it heats up? Now you know why.

So, it stands to reason that if a heavier barrel contour helps mitigate barrel movement by keeping those harmonic waves smaller, then shorter barrels must have oscillations of smaller amplitude than longer barrels, which equates to less barrel motion at the muzzle. Ergo, because there is less flex, less harmonic vibration and less muzzle whip, they are stiffer and thus potentially more precise. With that information, it is reasonable to assume and it is in fact true that, shorter barrels with the same barrel profile will be stiffer than longer barrels and that is why shorter barrels are actually more precise than longer barrels.

Additional advantages of shorter barrels are that they allow the use of a heavier contour without making the rifle unwieldy. A short rifle barrel is lighter and easier to carry than a long barreled rifle. Short barrels are also faster to react with. Short barrels can also prove to be very convenient in steep country or heavy brush where long barrels may get hung up or limit movement.

Some might ask, “What about muzzle blast and muzzle flash? Isn’t that a problem with a short barrel?” Those are valid concerns as shorter barrels do increase the muzzle blast and muzzle flash somewhat, but not as much as you would think with rifle barrels. The actual differences between a 24 or 26-inch barrel and an 18 or 20-inch barrel are negligible. Only when magnum cartridges and slow burning powders are used in handguns, should one be concerned.

In summation, I will apply this final comment to my original statement that “Due to their shorter barrel lengths, snub nose revolvers are perceived to have less precision than firearms with longer barrels. This is not true. Short barrels are in fact intrinsically more precise. The shorter sight radius, however, does make them more difficult to shoot accurately with precision.” We can also add to that, in the context of the short barrel on a defensive handgun that the shorter, stiffer barrel is more easily concealed, lighter to carry, and is less likely to be taken from you in a struggle.

And that my friend is why, “Thin may be in But Short and Fat is Where it’s At!”

What’s your call? Do you agree with the author? Why or why not? Share your answers in the comment section.