Muzzle Brakes in World War II

Muzzle Brakes Were Used Extensively in World War II

A World War II Panther tank seized by Kiel, Germany, police in 2015. The owner reportedly owned the Panther illegally (Autoevolution).

Muzzle brakes are those odd little perforated areas that you sometimes see at the end of a gun barrel. Guns without muzzle brakes are cylindrical and end that way, but some guns have these odd little muzzle brake contrivances at the end that you can see through. Obviously, they are not part of the regular barrel but added on to some barrels for some reason. So, let's explore muzzle brakes and find out how they were used during World War II.

A Junkers Ju 88P-5 medium bomber fitted with an 88 mm gun. This was only a prototype and apparently never used in combat. The gun has an elaborate muzzle brake.

Incidentally, at the end of this article are two special cases in which the Germans used muzzle brakes in "wonder weapons" that you may not have heard of.

What Are Muzzle Brakes?

German antitank guns of the normal type. At the left is the 3.7-cm Pak; at the right, the 5-cm Pak 38; in the rear, the 7.5-cm Pak 40. Note the muzzle brakes on the rear two guns.

Muzzle brakes alter the direction of gases as they exit the barrel of a gun that has just been fired. This produces certain effects on the gun and how the gases and flash disperse that the user of the gun may find desirable (or, for that matter, undesirable). You have probably heard of a pistol "silencer" used by assassins in fiction. A muzzle brake may be thought of as a variation on a gun silencer, though they have different effects and purposes. Theoretically, you may put a muzzle brake on any barrel, but some barrels will never have a muzzle brake for reasons we will get to below.

A prototype German self-propelled Artillery Tank showing its muzzle brake. This was the 10.5 cm K gepanzerte Selbstfahrlafette ("10.5cm gun on armored self-propelled mount") "Dicker Max." While sporting a powerful gun, the Dicker Max was slow and its gun had limited traverse, so the Wehrmacht did not like it. One prototype caught fire and burned up, but the other fought in the Soviet Union throughout 1941 and was lost in combat sometime in 1942.

This is not a topic of simply historical interest. Muzzle brakes are used in the 21st Century. In fact, the most advanced guns in the United States Army arsenal, a 155 mm cannon capable of striking targets to 70 kilometers, is projected to use muzzle brakes. However, a muzzle brake is not necessary for any particular gun. Whether or not a muzzle brake is desirable depends upon the purpose of the gun.

The current M109A6 Paladin sports a sophisticated muzzle brake (US Army photo).

You could have two identical guns, one with and one without a muzzle brake and each would serve their specialized functions better than the other. It depends on their missions. You add a muzzle brake, they are not required, and sometimes a muzzle brake would completely destroy the purpose of the gun. So, adding a muzzle brake requires a thoughtful decision. You will find experts with a decided preference for either using muzzle brakes or not, but this is a technical matter for a particular gun in a particular use. In other words, it really is not a matter of opinion, there is an answer for whether a muzzle brak will be helpful in a particular situation.

Muzzle brakes are not just for the military. Here is a current muzzle brake for sportsmen (Holland's Shooter Supply, Inc.).

So, whether to use a muzzle brake is not a "one size fits all" decision. Aside from that, some people just think that they "look cool." However, leaning one way or the other regarding whether to use muzzle brakes is sort of like saying that you prefer forks to knives: each setup has its purpose and there is no "one size fits all."

The History of Muzzle Brakes

A Sd.Kfz. 124 Wespe (German for "wasp"), also known as Leichte Feldhaubitze 18/2 auf Fahrgestell Panzerkampfwagen II (Sf.) ("Light field howitzer 18 on Panzer II chassis (self-propelled)"). A total of 676 Wespes were built with guns and an additional 159 without guns for various transport tasks.

It is unclear when muzzle brakes were invented. There are patents for muzzle brakes, but they are for specific types of muzzle brakes, not for the overarching concept of a muzzle brake. If this seems odd, just consider that there is no patent for the wheel, or for fire, or for the concept of building a craft that floats on the water. You'd be laughed out of the patent office if you tried to patent something like that. For all we know, the idea may extend back into the Middle Ages and the first use of weapons with barrels.

A Panzerkampfwagen IV Ausf.H of the Hitler Youth Division on maneuvers in Belgium in late 1943.

The first historical record of a muzzle brake occurred in 1842. French colonel Chevalier Treville de Beaulieu drilled holes into the muzzle region of a rifle. He drilled the holes so that they were sloped backward. This caused some of the gases when the gun was fired to be redirected backward, toward the rifleman. Around 1862, the French military tried this on a 160-mm naval gun. The designs proved to be successful, according to De Beaulieu, in doubling the accuracy of the gun and reducing the recoil distance by 75% of its normal distance. This was accomplished with a loss of only 6% (1/16th) of muzzle velocity. We'll get into how muzzle brakes work and why De Beaulieu got those results (which sound very plausible) below.

A knocked-out German Panther showing its muzzle brake during the summer of 1944 on the Eastern Front.

The British, being very interested in this sort of thing, got wind of the French experiments and not-so-coincidentally also conducted experiments on muzzle brakes in 1862 using a bronze 9-pounder gun. Their experiments, however, were not quite so promising, as the tests showed a disqualifying reduction in gun velocity and range. Gun crews also complained about the redirection of gases and noise in their general direction. Of course, this likely had to do with the exact design of the holes in the barrel, but this was a very early stage of the development of muzzle brakes and the British can't be faulted for not getting it right (probably on a spy's incomplete information) the first time. The difference in the French and British experiments shows how critical the precise design of the holes in a barrel is in creating an effect. Muzzle brakes did not exactly take the world by storm, but everyone knew there might be some use for them in the future.

An Italian Beretta Model 38 9mm with muzzle brake. The brake on this gun directed the muzzle blast upward to counteract the tendency of the gun to rise when fired. This is considered an exceptional submachine gun.

Naturally, the Germans took up the design challenge as well, but they went about it from a different direction. In 1888, engineer Haussner came up with a recoil system. He and other designers applied the French idea of muzzle brakes to his own "buffer-recuperator" recoil system to minimize the strain on gun carriages. So, it was only when other problems were solved that the true usefulness of muzzle brakes came into view. However, not much was done with them because the old guns worked just fine and there was no reason to rock the boat.

British Boys Antitank Rifle in use at practice during 1940. Note the circular muzzle brakes. This weapon was designed by Captain Henry Boys and produced by the Royal Small Arms Factory. It was capable of knocking out a light tank and remained useful against some targets throughout the war. 

World War I gave everyone a reason to look for any advantage, so muzzle brakes received renewed scrutiny. French engineers Galliot and Bory invented a muzzle brake which they named the "Galliot brake" that was theoretically effective but in real-world terms a non-starter.

Nice view of some muzzle brakes in action during World War II.

During the inter-war period, the United States developed the M1Thompson submachine gun to use a muzzle brake. This is the gun that you see in 1930s gangster movies being fired from cars as they drive by rival gangs. The Auto Ordnance Company developed a muzzle brake for the "Tommy gun" in 1921. Other armies continued developing muzzle brakes for various weapons, and by World War II, they were at a sufficient state of development to be applied to gun barrels ranging from pistols to tanks.

Why Would You Want To Use A Muzzle Brake?

From the earliest experiments in France, muzzle brakes have been shown to reduce recoil and improve accuracy. However, those experiments and similar British experiments showed that this was accomplished with some reduction (which could be very great) in muzzle velocity. While muzzle velocity is not always of prime importance, it is something that engineers try to maximize for the range and power of the shot. So, whenever you use a muzzle brake, you are trading muzzle velocity for some other benefits. Whether that trade-off is worthwhile depends on what you are using the weapon for.

A standard 3-man German machine-gun squad with their MG-34.

Muzzle brake basics are, well, basic: some type of opening on the muzzle end of the weapon allows some gases to go toward the side or rear rather than forward. The trick is how you design the muzzle brake to divert the gases in a particular way, and that is where people and companies get their patents. Without going into a lengthy discourse which, if you get very serious about this, involves a lot of mathematical formulae, the principal benefits of muzzle brakes are:

• Reduce recoil by 50% or more
• Improve accuracy (the barrel does not rise as much)
• They are often (not always) detachable in case you don't need them
• They look cool and dangerous, like some special thing that makes the gun even deadlier than usual
• Muzzle brakes make your firing position less obvious to the enemy by redirecting the flash and smoke in a lateral direction where it is less noticeable

Reducing recoil is especially important for a number of reasons, including saving wear and tear on the gun itself. However, in other situations, concealment may be the most important advantage.

A knocked-out German StuG III antitank gun near a destroyed Sherman tank in France late in the war. The StuG is presenting its muzzle brake nicely (Clifford O. Bell, collection of Charles D. Palmer). 

The major disadvantages of muzzle brakes are:

• They reduce muzzle velocity, so your shot has less range and power (usually by a fairly small degree)
• They can be expensive to design and manufacture
• They magnify the gun's noise to the gunner
• The redirected blast can be dangerous to the gunner or bystanders
• They usually add weight
• They may add length to the barrel, making the weapon more difficult to, say, move through city streets
• The redirected gases can damage the gun itself or the scope
• Muzzle brakes wear out fairly quickly due to tiny impacts

You may think up other advantages and disadvantages, but those are the ones most often considered when deciding whether to add a muzzle brake to a gun barrel.

The classic MG-42 used a muzzle brake when in service as a heavy machine gun.

Just to illustrate some extremes, let's look at situations where a muzzle brake might be particularly advantageous or undesirable. You will never see a muzzle brake on a battleship's main gun. The side blast would be extremely hazardous to both the ship and its crew, and in any event, main guns are intended to have maximum power and range, not precision at close range. On the other hand, a muzzle brake might be ideal for an artillery piece firing from a mountainside in view of the enemy, where you would not want them to spot your position as you rain fire down upon them. You would willingly trade a little range for accuracy and concealment. Or, a muzzle brake may be absolutely necessary when a gun is in a turret (such as a British Army Firefly) where there simply isn't enough room for a recoil. In fact, this latter situation is why you see muzzle brakes on so many tanks and assault guns.

British Firefly at the Bovington Tank Museum in 2014. The Firefly, considered one of the best British tanks of World War II, was only possible because the muzzle brake enabled an oversized gun to fit into the Sherman tank turret (The Online Tank Museum).

So, muzzle brakes definitely have their uses. They are not, however, something that you necessarily need or want in all situations. Having a muzzle brake is a choice that you don't always want to make.

How Did World War II Combatants Use Muzzle Brakes?

The 1944 model of the Japanese Type 100 submachine gun. This had two ports drilled into the barrel to serve as a muzzle brake.

The Japanese did not use muzzle brakes as much as other combatants. One example was the Type 100 submachine gun, the only submachine gun that Japan produced in quantity during World War II (based on the SIG Bergman 1920, itself a licensed Swiss version of the German MP 18). However, the muzzle brake on the Japanese Type 100 gun was only used on certain models. The early Japanese design was very complicated, suggesting they had not worked on muzzle brakes very much. However, by 1944, the Japanese simplified the design down to simply drilling two ports into the barrel - hard to get simpler than that.

Panzer VI Tiger I in Tunisia, June 1943. Note the muzzle brake (Pirath, Helmuth, Federal Archive Picture 101I-554-0872-35).

The Germans put muzzle brakes on many of their armored vehicles. These included the Tiger series, the Jagdpanther, the Panzer IV, and the StuG III. These armored vehicles constituted the heart of the Panzerwaffe (German tank force) late in the war. Some weapons that did not have muzzle brakes included the Panzer III, which was the Wehrmacht's main battle tank for the first two years of the war. Muzzle brakes in some models such as the Panzer III were disfavored due to the dust storm they raised, which obscured the crew's vision. Some artillery pieces such as the 5-cm Pak 38 and the 7.5-cm Pak 40 used muzzle brakes, too. Crews often removed muzzle brakes if they didn't like them because they kicked up too much dust or simply found them unnecessary. The classic MG 34 and MG 42, the latter considered perhaps the best weapon of its type during World War II, used a muzzle brake when used as a heavy machine gun.

A Finnish soldier who undoubtedly was the one to knock out this Soviet ISU-152 posing in front of his kill in Finland, 1944. The muzzle brake is clearly visible. The soldier may have used a Panzerfaust to knock it out (SA-Kuva).

The Soviet Union did not use muzzle brakes very much. This may have been because Soviet tactics favored head-on assaults where the sheer weight of firepower mattered most. So, the famous T-34, T-34/85, Su-85, and Su-100 did not use muzzle brakes. The most powerful Soviet tanks and artillery pieces usually did have muzzle brakes, however. This included the Joseph Stalin JS-2 with a 122mm main gun and the ISU-152.

An M18 Hellcat Tank Destroyer sporting a 76mm cannon with the muzzle brake (US National Archive).

The U.S. Army developed muzzle brakes for the 76 mm gun M1. The U.S. Ordnance Department ordered this weapon in 1942, and it was ready for testing in January 1944. Production began in June 1944 and they began arriving in numbers on battlefields in January 1945 aboard the M18 Hellcat.

A Sherman Firefly mounting a muzzle brake on the end of its 17-pounder anti-tank gun.

As discussed above, the British were one of the earliest powers to begin working on muzzle brakes. The 3-inch (76.2 mm) caliber British 17-pounder anti-tank gun was one result. The British converted about 2100 Sherman tanks into Sherman Firefly anti-tank weapons by replacing the main gun with the 17-pounder gun. The huge gun barely fit into the Sherman turret, so reducing recoil was necessary. The redesign was a spectacular success, and the Firefly was one of the few Allied tracked vehicles that could knock out Tiger and Panther tanks from long range.

A Special Case: The Panzerkampfwagen E 100 (Gerät 383) (TG-01)

An American soldier cleaning the muzzle brake on a captured E-100.

The Panzerkampfwagen E 100 (Gerät 383) (TG-01) was a German super-heavy tank which Adolf Hitler ordered developed. It was based on blueprints submitted during March 1944 by the Adler company in Frankfurt. German manufacturers were well aware of Hitler's penchant for massive weapons, an obsession which his senior generals such as Heinz Guderian did not share and did their best to frustrate. The plans called for the tank to carry both a 149 mm gun and a 75 mm gun. The smaller model would be powered by a 700-hp Maybach HL230 engine, a later model with a 1200-hp Maybach engine. Although Hitler originally ordered the production of a prototype, he changed his mind in July 1944 as he realized he needed weapons soon due to the June 1944 Allied invasion at Normandy. The Adler company did proceed at a minimal pace until the end of the war, when the 751st Field Artillery Battalion of the US Army found the partially complete prototype. The main gun had a massive muzzle brake which had been completed.

A Special Case: The Luftwaffe's Gerät 104 (Device 104) "Münchhausen."

The Junkers Ju 88P-5 "Duka" prototype with 88mm anti-tank cannon fitted with an elaborate muzzle brake.

As we've seen, muzzle brakes were in an advanced state of development by World War II. Their use was widely understood, and research on them continued throughout the war, particularly in Germany (Klaus Oswatitsch at the Gottingen Kaiser Wilhelm Institute of Flow Research) and Britain (Corner, in 1942) but also by other major powers. It is fair to state that any major power that wanted to build and use muzzle brakes during World War II could figure out how to do so, though some combatants found very little use for them.

Prototype Dornier Do-217 fitted with a Gerat 104 Münchhausen cannon, complete with massive muzzle brake.

The Germans used muzzle brakes extensively, as can be seen on the pictures on this page, and not just on the ground. The Luftwaffe had big plans, and those involved big guns. Big guns are feasible on planes if you can vastly reduce or eliminate the recoil, and muzzle brakes made that possible. The most elaborate plan was a Dornier Do-217 medium bomber fitted with a massive Gerät 104 (Device 104) "Münchhausen."

Plans for the airborne Gerät 104 (Device 104) "Münchhausen."

This was a 355.6 mm (14-inch) caliber prototype recoilless rifle designed in 1939. That is the kind of gun that appears as the main gun on battleships. The Luftwaffe's objective was to use the Gerät 104 (Device 104) "Münchhausen" to engage ships of the Royal Navy - from the air. The plane would attack as a dive bomber (all Luftwaffe bombs were designed to have this capability). This idea was actually tried beginning on 9 September 1940 but did not work because the blast caused extensive fuselage damage. In-air tests continued through 1941 but then were abandoned. In case you're wondering if this is make-believe - it isn't. The Luftwaffe actually did and tried this.

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