A muzzle brake or recoil compensator is a device connected to, or a feature integral to the construction of, the muzzle or barrel of a firearm or cannon that is intended to redirect a portion of propellant gases to counter recoil and unwanted muzzle rise. Barrels with an integral muzzle brake are often said to be ported.
The concept of a muzzle brake was first introduced for artillery. It was a common feature on many anti-tank guns, especially those mounted on tanks, in order to reduce the area needed to take up the strokes of recoil and kickback. They have been used in various forms for rifles and pistols to help control recoil and the rising of the barrel that normally occurs after firing. They are used on pistols for practical pistol competitions, and are usually called compensators in this context.
History
The concept of a muzzle brake had been experimented with for many years prior to its successful implementation: in 1922, a US Army Ordnance Department official stated in US Congress that "the muzzle brake was used in another form 20 years ago, and even longer ago than that, but it has never been successfully applied".
Antoine Treuille de Beaulieu invented a prototype based on the idea in 1842 and had it tested in 1862, but he himself called the idea "too new". A US patent was issued for a "recoil obviator" in 1871 (there is no indication it was ever tested), while an experimental British anti-tank rifle in 1918 featured a muzzle brake, but was not adopted.
In the later 1920s, there was some limited progress: around 1926, Cutts compensator became an option in the Thompson SMG (R. M. Cutts' earliest patent is from 1925), in 1927 Škoda patented a family of muzzle brake designs, one of which was used on 8 cm kanon vz. 28, and in 1928, Schneider et Cie (which was allied with Škoda at the time) updated their 220 mm TR mle 1915/1916 with a muzzle brake patented by Eugène Schneider II way back in 1912.
In mid-1930s, Bofors designed several successful artillery pieces (e. g. 37-mm and 105-mm guns) with new perforated muzzle brakes, so called pepper-pot muzzle brakes, a design invented by then Swedish artillery staff officer, captain Harald Jentzen, in Sweden known as a "Jentzen-brake" (). The Soviet Union started modernising old artillery systems with new barrels, such as the 107 mm gun M1910/30, 152 mm gun M1910/30, 152 mm gun M1910/34, etc, predominantly featuring cylindrical muzzle brakes with long slits on each side. Several European countries started designing and producing AT rifles featuring muzzle brakes. In late 1930s and especially during World War II the device became common on both firearms and artillery pieces.
Overall, the development of the muzzle brake was a gradual process that involved experimentation and refinement over many years.
Rationale in firearms
The interchangeable terms muzzle rise, muzzle flip, or muzzle climb refer to the tendency of a handheld firearm's front end (the muzzle end of the barrel) to rise after firing. Firearms with less height from the grip line to the barrel centerline tend to experience less muzzle rise.
The muzzle rises primarily because, for most firearms, the centerline of the barrel is above the center of contact between the shooter and the firearm's grip and stock. The reactive forces from the fired bullet and propellant gases exiting the muzzle act directly down the centerline of the barrel. If that line of force is above the center of the contact points, this creates a moment or torque (rotational force) that causes the firearm to rotate and the muzzle to rise. The M1946 Sieg automatic rifle had an unusual muzzle brake that made the rifle climb downward, but enabled the user to fire it with one hand in full automatic.
Design and construction
Muzzle brakes are simple in concept, such as the one employed on the 90 mm M3 gun used on the M47 Patton tank. This consists of a small length of tubing (mounted at right angles) at the end of the barrel. Brakes most often utilize slots, vents, holes, baffles, and similar devices. The strategy of a muzzle brake is to redirect and control the burst of combustion gases following the departure of a projectile.