What Does a Muzzle Brake Do? - Tank Historia

What Does a Muzzle Brake Do?

So, you’ve seen a tank and noticed a “thing” with holes in at the end of its gun barrel. You may have seen it on some tanks but not others, and asked yourself “What is this?”

This is a muzzle brake, and it serves an important purpose.

In this article we explain what this device is, what it does and how it works. Even if you already know why a muzzle brake is fitted, there may still be a few things you didn’t know.

Contents

The Muzzle Brake

Its best to start with what a muzzle brake actually is.

A muzzle brake is a device attached to the end of a gun barrel, and can be found on anything from a pistol to a 155 mm howitzer.

Top view of a muzzle brake.
A top view of a basic muzzle brake.

Some are removable, while others are fashioned straight out of the barrel itself.

In most cases a muzzle brake’s construction is simple.

The device allows a projectile to travel through it and usually has slots cut into its sides. These slots are are integral to its function.

One of the many designs of muzzle brake.
The size and shape of muzzle brakes depends heavily on the size, power and purpose of the gun. Image by Bin im Garten CC BY-SA 3.0.

Where they vary is in their size and shape – which is mostly dependant on the gun they are on.

So now we know what a muzzle brake is, now we want to know what they do, which is the important part.

What does the Muzzle Brake Do?

A muzzle brake’s primary function is to help reduce recoil.

More accurately, they help to control recoil.

When a gun is fired, a combustible charge behind the projectile is ignited, which produces rapidly expanding gases that push the projectile along the barrel and out the end (the muzzle).

However, this is where Newton’s third law comes in to play (for every action, there is an equal and opposite reaction). The same force used to push the projectile out the barrel is also exerted on the gun, pushing it backwards.

Projectile firing diagram
When a round is fired, the force pushing the shell out the barrel also pushes back equally on the gun itself.

This is known as recoil, and it is why guns and other weapons “kick” when fired.

This recoil needs to be managed, which is usually done by pushing against the gun. This may be done by the human body, but in something like a tank, hydraulic recoil mechanisms help to soften the blow.

These mechanisms slow the gun as it travels backwards, extending the duration of the recoil and therefore reducing the peak forces acting on the gun’s mount.

But as the gun increases in size or power, so does its recoil and as a consequence, the distance it needs to travel to slow it down.

Highlighted recoil mechanisms on an anti-tank gun.
The recoil cylinder (top) and recoil guides (bottom) highlighted red in this image help to reduce the recoil’s impact.

You may see where this is going.

In a tank space is limited, so a gun’s recoil mechanism needs all the help it can get in reducing a gun’s travel. Also, too much recoil is uncomfortable for the crew, can throw off a gun’s aim and even damage the vehicle.

Its beneficial to control recoil in other situations too, like someone shooting a powerful rifle.

Enter the muzzle brake.

The muzzle brake provides a little extra forward push on the gun, helping to reduce its kick.

How it Works

Muzzle brakes use the same expanding gasses that push a projectile out the barrel to also push the gun forward.

It does this by venting these gasses out of specifically designed holes. The escaping gasses push on the muzzle in the opposite direction.

Holes mounted on top of the muzzle will push it downwards, which is mostly seen on small arms.

Most tank muzzle brakes vent the gasses sideways and slightly backwards, so they actually push the gun forwards, opposing the gun’s recoil.

Projectile leaving the barrel.
Once the projectile passes the muzzle brake, the propellant gasses are vented out the sides of the muzzle brake, pushing forwards on the gun.

The amount a muzzle brake helps to control recoil can vary massively depending on the gun and muzzle brake design, but in some cases they can reduce recoil effects by up to 50 percent.

This could be enough of a difference to fit a gun inside a turret of a tank and have enough space for it to travel backwards.

Other Advantages

Muzzle brakes can bring a few more things to the table than just recoil management too.

They can massively help to control the plume of smoke that exits the barrel after firing. For a gunner on a large caliber weapon, this smoke cloud can obscure their view of the target, making follow up shots harder or even completely impossible.

By venting the gasses to the sides, it keeps the view to the target clear.

Muzzle brake helping to maintain vision.
The blasts of large guns can completely obscure the crew’s view of the target. Muzzle brakes help reduce this.

Similarly, by directing the gasses sideways muzzle brakes can limit the amount of dust kicked up after firing, which prevents an enemy from spotting your location.

If a muzzle brake controls recoil, keeps a tank’s sights clear and helps keep dust down, why don’t all vehicles use them?

Well, as with anything, muzzle brakes are not suited to every single situation, and can sometimes be a problem.

Disadvantages

One of the basic disadvantages of a muzzle brake is added cost and complexity. For many vehicles, the gains far outweigh the costs, but for others it is simply not worth it.

Many WWII era “casemate” style vehicles lacked a muzzle brake, as they had plenty of room inside for the gun to recoil. The costs and extra materials to add a muzzle brake was not justified.

Similarly, some guns have such low velocities that they do not need a muzzle brake. Others never received them as they can offset the gun’s delicate balance.

However, on modern main battle tanks (MBTs), muzzle brakes are not suited to the ammunition they use.

Sabot round fired.
Sabot rounds allow a smaller projectile (sub-caliber) to be fired from a larger gun.

MBTs today often use discarding sabot rounds. A sabot is a jacket that fits around a projectile and allows it to be fired from a gun of a larger calibre (think of a pencil being fired from a wider tube).

When these rounds leave the barrel the sabot jacket tears off the projectile, which then travels at extremely high speeds to the target.

Discarding sabot rounds cannot be used with a muzzle brake, as the sabot can impact the brake, causing damage and interfering with the projectiles flight path.

Sabot round discarding
Once the round leaves the barrel, the sabot surrounding the projectile peels away. As you can see, this could be disastrous when fired through a muzzle brake.

Fin stabilised rounds cannot be used either, as the brake would interfere with the spring-loaded fins.

Despite being much less common today, the muzzle brake can still be found on some modern vehicles and weapons platforms. On the other hand, it has become more popular on small arms, such as the Barrett M82 anti-material rifle.

Another Article From Us: Why do Tanks use Angled Armor?

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So, next time you see a vehicle with strange looking device on the end, it is no longer a mystery.