How Does Barrel Length Affect a Gun?

How Does Barrel Length Affect a Gun?

Most of us have heard chatter about gun barrel length on shooting ranges, with some gun gurus claiming that barrel length is the most important factor or that it dramatically affects accuracy. Other guys might go the opposite route and claim that barrel length is a fake factor: it doesn’t matter at all!

The truth is somewhere in the middle. How does barrel length affect a gun and how well it performs? Let’s break it down.

ACCURACY

The most commonly touted benefit of longer firearm barrels is that they provide their guns with greater accuracy. As a result, many long-distance hunters or sharpshooters will swear by long barrels, even to the expense of other features. But does this really matter?

In truth, yes, but not necessarily because of what you think. Barrel length doesn’t directly impact accuracy by improving bullet projection. Instead, longer barrels usually produce more accuracy since they offer longer sighting planes whenever you combine a gun with excellent sights or optics.

Consider a gun that has a sight both on the rear and near the front of a gun’s barrel. The longer the barrel distance between those sights, the more accurate the sighting plane (and, thus, the gun) will end up being.

Another good way to look at this is your gun’s accuracy is more impacted by how many sights you have and the quality of those sights. If you only have a single sight, the barrel doesn’t matter as much for accuracy.

RECOIL

Barrel length does have a minor effect on gun recoil, though this is tough to test and isn’t as big of a factor as other advantages or effects. A firearm with a longer barrel will have less recoil only because such a firearm is likely heavier than an identical counterpart with a shorter barrel. If the gun is heavier, it takes more power for it to produce the same amount of recoil.

How much does barrel length matter for recoil? An inch or so of barrel adds a couple of ounces in weight for some firearms, though this is dependent on the gun’s materials. Some guns use naturally heavier materials, while others use really lightweight materials. In the latter’s case, a longer barrel won’t affect recoil all that much.

MUZZLE VELOCITY

Some firearm enthusiasts think that the myth of the barrel length affecting muzzle velocity is overblown. But in truth, barrel length can often affect each cartridge’s overall velocity… but it’s a bit more complicated than a flat benefit.

In brief, your cartridge’s velocity has little to do with your weapon and everything to do with the cartridge itself. Specifically, your cartridges use either fast or slow-burning powder. Fast-burning powders create a rapid explosion in the barrel of a given gun. They reach their maximum velocities quickly and would actually be a little slowed down if they were used in guns with long barrels. Slow-burning powder takes more time to ramp up its explosive velocity. A longer barrel gives a slow-burning-powder cartridge more time to gather speed and power. 

So, can a longer barrel make your weapon’s muzzle velocity higher? Yes, if you combine a long barrel with a particularly slow-burning powder - you’ll produce a faster bullet explosion overall than if you used the same cartridge with a shorter barrel.

The minute differences between velocities are mostly noticed by hand reloaders. These enthusiasts make their own ammo, so they pick out the powder and can formulate a cartridge load that’s perfect for their guns’ barrel lengths.

Note that there is such a thing as diminishing returns when it comes to barrel length improving muzzle velocity. This isn’t normally an issue, but if you try to use a powder that isn’t slow-burning enough with a barrel that’s too long, you’ll end up with a slower-than-average muzzle velocity since the cartridge will rub against the barrel for longer as it comes out.

NOISE

Lastly, barrel length can have an effect on the noise of your gun. Let’s break it down.

The explosive bang produced by a firearm occurs when a bullet, and the trailing explosion in the barrel, both exit the barrel at incredible speeds. The pressure and heat of the explosion cause the air inside the barrel to expand rapidly.

This explosion’s noise level is affected by several things:

  • The type of powder used – more powerful powders will produce louder explosions
  • The weather – sometimes cold or hot weather can affect gun noise
  • Barrel length – yes, this can also affect gun noise

Longer barrels give a bullet’s explosion more time to complete inside the barrel before both the round and the air are expelled. This results in a somewhat quieter bang when all other factors are equal. If you have two rifles using the exact same cartridges, the one with the longer barrel will be a bit quieter.

However, many rifles use higher-powered cartridges to hit targets at far ranges. This, in turn, may negate any silencing effect that a longer barrel might passively provide. Besides, the noise difference isn’t so drastic that it would make much of a difference in most hunting scenarios.

CONCLUSION

All in all, barrel length is certainly something you should keep in mind when buying a weapon and when considering whether it’ll be a good fit for a certain activity. However, remember that many other factors aside from barrel length can impact weapon performance and accuracy. 

Happy shooting!