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Muzzle energy is the kinetic energy of a bullet as it is expelled from the muzzle of a firearm. Without consideration of factors such as aerodynamics and gravity for the sake of comparison, muzzle energy is used as a rough indication of the destructive potential of a given firearm or cartridge. The heavier the bullet and especially the faster it moves, the higher its muzzle energy and the more damage it will do.
The general formula for the kinetic energy is
where v is the velocity of the bullet and m is the mass of the bullet.
Although both mass and velocity contribute to the muzzle energy, the muzzle energy is proportional to the mass while proportional to the square of the velocity. The velocity of the bullet is a more important determinant of muzzle energy. For a constant velocity, if the mass is doubled, the energy is doubled; however, for a constant mass, if the velocity is doubled, the muzzle energy increases four times. In the SI system the above Ek will be in unit joules if the mass, m, is in kilograms, and the speed, v, is in metres per second. [1]
Muzzle energy is dependent upon the factors previously listed, and velocity is highly variable depending upon the length of the barrel a projectile is fired from. [2] Also the muzzle energy is only an upper limit for how much energy is transmitted to the target, and the effects of a ballistic trauma depend on several other factors as well. There is wide variation in commercial ammunition. A 180 gr (12 g) bullet fired from .357 Magnum handgun can achieve a muzzle energy of 580 ft⋅lbf (790 J). A 110 gr (7.1 g) bullet fired from the same gun might only achieve 400 ft⋅lbf (540 J) of muzzle energy, depending upon the manufacturer of the cartridge. Some .45 Colt +P ammunition can produce 1,200 ft⋅lbf (1,600 J) of muzzle energy.[ citation needed ]
Many parts of the world use muzzle energy to classify guns into categories that require different categories of licence. In general guns that have the potential to be more dangerous have tighter controls, while those of minimal energy, such as small air pistols or air rifles, require little more than user registration, or in some countries have no restrictions at all. Overview of gun laws by nation indicates the various approaches taken. Firearms regulation in the United Kingdom is a complicated example, but is demarked by muzzle energy as well as barrel length and ammunition diameter.
Some jurisdictions also stipulate minimum muzzle energies for safe hunting. For example, in Denmark rifle ammunition used for hunting the largest types of game there such as red deer must have a kinetic energy E100 (i.e.: at 100 m (110 yd) range) of at least 2,700 J (2,000 ft⋅lbf) and a bullet mass of at least 9 g (140 gr) or alternatively an E100 of at least 2,000 J (1,500 ft⋅lbf) and a bullet mass of at least 10 g (150 gr). [3] Namibia specifies three levels of minimum muzzle energy for hunting depending on the size of the game, 1,350 J (1,000 ft⋅lbf) for game such as springbok, 2,700 J (2,000 ft⋅lbf) for game such as hartebeest, and 5,400 J (4,000 ft⋅lbf) for Big Five game, together with a minimum caliber of 7 mm (0.28 in). [4]
In Germany, airsoft guns with a muzzle energy of no more than 0.5 J (0.37 ft⋅lbf) are exempt from the gun law, [5] while air guns with a muzzle energy of no more than 7.5 J (5.5 ft⋅lbf) may be acquired without a firearms license. [6]
Mainland China uses a varied concept of "muzzle ratio kinetic energy" (Chinese :枪口比动能), which is the quotient (ratio) of the muzzle energy divided by the bore cross sectional area, to distinguish genuine guns from "imitation" replicas like toy guns. The Ministry of Public Security unilaterally introduced the concept in 2008 leading up to the Beijing Olympic Games, dictating that anything over 1.8 J/cm2 to be defined as real firearms. This caused many existing toy gun products on the Chinese market (particularly airsoft) to become illegal overnight, as almost all airsoft guns shooting a standard 0.20 g (3.1 gr) 6 mm (0.24 in) pellet have a muzzle velocity over 76 m/s (250 ft/s), which translates to more than 0.58 J (0.43 ft⋅lbf) of muzzle energy, or 2.0536 J/cm2 of "ratio energy". For comparison a standard baseball changeup thrown at 34 m/s (110 ft/s) has 1.951 J/cm2 of "ratio energy" which also exceeds the 1.8 J/cm2 of a real firearm while a fastball can reach over 3.5 J/cm2 or nearly double the level of a real firearm. The subsequent crackdowns by local law enforcement led to many seizures, arrests and prosecutions of individual owners for "trafficking and possession of illegal weapons" over the years for weapons that were previously permitted.
Airsoft, also known as survival game in Japan where it was popular, is a team-based shooting game in which participants eliminate opposing players out of play by shooting them with spherical plastic projectiles shot from airsoft guns.
Recoil is the rearward thrust generated when a gun is being discharged. In technical terms, the recoil is a result of conservation of momentum, as according to Newton's third law the force required to accelerate something will evoke an equal but opposite reactional force, which means the forward momentum gained by the projectile and exhaust gases (ejectae) will be mathematically balanced out by an equal and opposite momentum exerted back upon the gun.
From the viewpoint of physics, a firearm, as for most weapons, is a system for delivering maximum destructive energy to the target with minimum delivery of energy on the shooter. The momentum delivered to the target, however, cannot be any more than that on the shooter. This is due to conservation of momentum, which dictates that the momentum imparted to the bullet is equal and opposite to that imparted to the gun-shooter system.
Muzzle velocity is the speed of a projectile with respect to the muzzle at the moment it leaves the end of a gun's barrel. Firearm muzzle velocities range from approximately 120 m/s (390 ft/s) to 370 m/s (1,200 ft/s) in black powder muskets, to more than 1,200 m/s (3,900 ft/s) in modern rifles with high-velocity cartridges such as the .220 Swift and .204 Ruger, all the way to 1,700 m/s (5,600 ft/s) for tank guns firing kinetic energy penetrator ammunition. To simulate orbital debris impacts on spacecraft, NASA launches projectiles through light-gas guns at speeds up to 8,500 m/s (28,000 ft/s). FPS and MPH are the most common American measurements for bullets. Several factors, including the type of firearm, the cartridge, and the barrel length, determine the bullet's muzzle velocity.
The .22 Long Rifle, also known as the .22LR or 5.6×15mmR, is a long-established variety of .22 caliber rimfire ammunition originating from the United States. It is used in a wide range of firearms including rifles, pistols, revolvers, and submachine guns.
The .22 Long is a variety of .22 caliber (5.6 mm) rimfire ammunition. The .22 Long is the second-oldest of the surviving rimfire cartridges, dating back to 1871, when it was loaded with a 29 gr (1.9 g) bullet and 5 gr (0.32 g) of black powder, 25% more than the .22 Short on which it was based. It was designed for use in revolvers, but was soon chambered in rifles as well, in which it gained a reputation as a small game cartridge.
A shotgun slug is a heavy projectile made of lead, copper, or other material and fired from a shotgun. Slugs are designed for hunting large game, and other uses, particularly in areas near human population where their short range and slow speed helps increase safety margin. The first effective modern shotgun slug was introduced by Wilhelm Brenneke in 1898, and his design remains in use today. Most shotgun slugs are designed to be fired through a cylinder bore, improved cylinder choke, rifled choke tubes, or fully rifled bores. Slugs differ from round ball lead projectiles in that they are stabilized in some manner.
The 5.45×39mm cartridge is a rimless bottlenecked intermediate cartridge. It was introduced into service in 1974 by the Soviet Union for use with the new AK-74. The 5.45×39mm gradually supplemented and then largely replaced the 7.62×39mm cartridge in Soviet and Warsaw Pact service as the primary military service rifle cartridge.
The .460 S&W Magnum round is a powerful revolver cartridge designed for long-range handgun hunting in the Smith & Wesson Model 460 revolver.
Airsoft is a sport in which players use airsoft guns to fire plastic projectiles at other players in order to eliminate them. Due to the often-realistic appearance of airsoft guns and their ability to fire projectiles at relatively high speeds, laws have been put in place in many countries to regulate both the sport of airsoft and the guns themselves. Safety regulations in many areas require an orange or red tip on the end of the barrel in order to distinguish the airsoft gun from a working firearm. They are officially classed as "soft air devices" or "air compressed toys", depending on the jurisdiction. A handful of countries including Australia, Malaysia, and Singapore have laws that are deemed to be airsoft-unfriendly.
The .338 Winchester Magnum is a .338 in (8.6 mm) caliber, belted, rimless, bottlenecked cartridge introduced in 1958 by Winchester Repeating Arms. It is based on the blown-out, shortened .375 H&H Magnum. The .338 in (8.6 mm) is the caliber at which medium-bore cartridges are considered to begin. The .338 Winchester Magnum is the first choice among professional brown bear guides in Alaska to back up clients where a powerful stopping caliber is required on charging bears. It is also the most popular medium-bore cartridge in North America and has the most widely available choice in rifles among medium bore rifles. The action length is the same as a .30-06, and most major rifle manufacturers in the United States chamber rifles for the cartridge including the semi-automatic Browning BAR Mk II Safari, making it a very powerful combination against charging dangerous game. The cartridge was intended for larger North American big-game species and has found use as for the hunting of thin-skinned African plains-game species.
Airsoft pellets are spherical projectiles used by airsoft guns. Typically made of plastic, they usually measure around 6 mm (0.24 in) in diameter, and weigh 0.20–0.40 g (3.1–6.2 gr), with the most common weights being 0.20 g and 0.25 g, while 0.28 g, 0.30 g, 0.32 g and 0.40 g BBs are also commonplace. Though frequently referred to as "BBs" among airsoft users, these BBs are not the same as either of the 4.5 mm metal projectiles that BB guns fire, or the 4.6 mm (0.180 in)-sized birdshot from which the term "BB" originated.
The 4.5mm MKR, also known as the 4.5mm Interdynamic or 4.5mm Kjellgren, was a Swedish prototype rimfire cartridge developed for the prototype Interdynamics MKR bullpup assault rifle and carbine.
Free recoil is a vernacular term or jargon for recoil energy of a firearm not supported from behind. Free recoil denotes the translational kinetic energy (Et) imparted to the shooter of a small arm when discharged and is expressed in joules (J), or foot-pound force (ft·lbf) for non-SI units of measure. More generally, the term refers to the recoil of a free-standing firearm, in contrast to a firearm securely bolted to or braced by a massive mount or wall. Free recoil should not be confused with recoil:
The spitzer bullet is a pointed projectile that is primarily used in small-arms. The pointed nose shape, which was developed for military purposes in the late 19th and early 20th century, was a major design improvement compared to earlier rounder or flatter-tipped bullets because pointed nose shapes were less susceptible to external ballistic factors like drag. By adding a point, projectiles made for fully-powered and intermediate rifle cartridges obtain a lower drag coefficient, which makes them decelerate less rapidly. Lowering the drag coefficient leads to improved external ballistic behaviour.
The .327 Federal Magnum is a cartridge introduced by Federal Premium Ammunition and also sold by Sturm, Ruger & Co. It is intended to provide the power of a .357 Magnum in six-shot, compact revolvers, whose cylinders would otherwise only hold five rounds. The .327 has also been used in full-sized revolvers with a capacity of seven rounds or more. The .327 Federal Mag is an example of a "super magnum", because it is a magnum of a magnum, the .32 H&R Magnum.
Power factor (PF) in practical shooting competitions refers to a ranking system used to reward cartridges with more recoil. Power factor is a measure of the momentum of the bullet, which to some degree reflects the recoil impulse from the firearm onto the shooter.
This is a list of laws concerning air guns by country.
The .500 A-Square is a belted, bottleneck rifle cartridge, developed by Arthur Alphin in 1976. The cartridge is based on the .460 Weatherby Magnum necked up to accept the .510 in (13.0 mm) bullet; the same as the .50 BMG cartridge. This was Col. Alphin's first commercial sporting cartridge and was designed in “response to some severe problems experienced with the .458 Winchester on safari in Mozambique.”
The .500 S&W Magnum or 12.7×41mmSR is a .50 caliber semi-rimmed revolver cartridge developed by Cor-Bon in partnership with the Smith & Wesson "X-Gun" engineering team for use in the Smith & Wesson Model 500 X-frame revolver and introduced in February 2003 at the SHOT Show. From its inception, it was intended to be the most powerful handgun cartridge to date, with the capacity to harvest all North American game species. While more powerful handgun cartridges, such as the .500 Bushwhacker, have emerged since, they are only available in custom firearms, and the .500 S&W remains the most powerful production handgun cartridge.
