Recoil - Revision history

Lwcamp at 19:05, 7 March 2026

2026-03-07T19:05:50Z

← Older revision		Revision as of 12:05, 7 March 2026
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	Authors: Phoenix, Tshhmon, and Luke Campbell.		Authors: Phoenix, Tshhmon, and Luke Campbell.

	[[Category:Military Technology]][[Category:Warfare]][[Category:Engineering‏‎]]		[[Category:Military Technology]][[Category:Warfare]][[Category:Engineering‏‎]][[Category:Physics & Math & Engineering]]

Lwcamp: /* Recoil for Electromagnetic Launchers */

2025-11-27T03:06:16Z

Recoil for Electromagnetic Launchers

← Older revision		Revision as of 20:06, 26 November 2025
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	==Recoil for Electromagnetic Launchers==		==Recoil for Electromagnetic Launchers==

	[[File:Comparison_of_the_recoil_of_conventional_and_electromagnetic_cannon.~~jpg~~\|thumb\|A comparison of the recoil impulse from a powder gun (green), electromagnetic gun (red), and a powder gun with a muzzle brake (blue) for a constant-energy launch (varying the mass of the projectile with speed to keep the total kinetic energy constant). Data from <ref>Edward M. Schmidt, "Comparison of the recoil of conventional and electromagnetic cannon", Shock and Vibration 8 (2001) 141–145 https://doi.org/10.1155/2001/590948</ref>]]An [[Electromagnetic_guns\| electromagnetic launcher]] is a device that uses electromagnetic fields and electric currents to push or pull a projectile. For a coilgun, the recoil is straightfoward - the fields of the projectile while it is being accelerated push or pull on the currents in the coils the same amount that the fields from the coils push or pull on the currents in the projectile (for a magnetic projectile, these can be the net currents you get by aligning the spins and angular momenta of the electrons around the atoms in the magnet - they're not the sort of currents that can be measured by a multi-meter, but they still physically exist and make and interact with magnetic fields). So for a coilgun, you directly get the impulse on the projectile being the impulse on the gun in an obvious way.		[[File:Comparison_of_the_recoil_of_conventional_and_electromagnetic_cannon.png\|thumb\|A comparison of the recoil impulse from a powder gun (green), electromagnetic gun (red), and a powder gun with a muzzle brake (blue) for a constant-energy launch (varying the mass of the projectile with speed to keep the total kinetic energy constant). Data from <ref>Edward M. Schmidt, "Comparison of the recoil of conventional and electromagnetic cannon", Shock and Vibration 8 (2001) 141–145 https://doi.org/10.1155/2001/590948</ref>]]An [[Electromagnetic_guns\| electromagnetic launcher]] is a device that uses electromagnetic fields and electric currents to push or pull a projectile. For a coilgun, the recoil is straightfoward - the fields of the projectile while it is being accelerated push or pull on the currents in the coils the same amount that the fields from the coils push or pull on the currents in the projectile (for a magnetic projectile, these can be the net currents you get by aligning the spins and angular momenta of the electrons around the atoms in the magnet - they're not the sort of currents that can be measured by a multi-meter, but they still physically exist and make and interact with magnetic fields). So for a coilgun, you directly get the impulse on the projectile being the impulse on the gun in an obvious way.

	For railguns, the situation is a bit more complicated. The magnetic forces in the railgun push the rails apart, not backward. So the impulse on the projectile is not countered by the impulse on the rails. Instead, the railgun is pushed back where the circuit is closed at the back end of the rails. Where the current completes the circuit in the driving generators and electronics (and power couplings if the generation is kept distant from the rails) is where the recoil is generated, from the same sort of action of the magnetic field on the current that also propels the bullet down the rails.		For railguns, the situation is a bit more complicated. The magnetic forces in the railgun push the rails apart, not backward. So the impulse on the projectile is not countered by the impulse on the rails. Instead, the railgun is pushed back where the circuit is closed at the back end of the rails. Where the current completes the circuit in the driving generators and electronics (and power couplings if the generation is kept distant from the rails) is where the recoil is generated, from the same sort of action of the magnetic field on the current that also propels the bullet down the rails.

Lwcamp: /* Recoil for Electromagnetic Launchers */

2025-11-27T03:05:52Z

Recoil for Electromagnetic Launchers

← Older revision		Revision as of 20:05, 26 November 2025
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	==Recoil for Electromagnetic Launchers==		==Recoil for Electromagnetic Launchers==

	An [[Electromagnetic_guns\| electromagnetic launcher]] is a device that uses electromagnetic fields and electric currents to push or pull a projectile. For a coilgun, the recoil is straightfoward - the fields of the projectile while it is being accelerated push or pull on the currents in the coils the same amount that the fields from the coils push or pull on the currents in the projectile (for a magnetic projectile, these can be the net currents you get by aligning the spins and angular momenta of the electrons around the atoms in the magnet - they're not the sort of currents that can be measured by a multi-meter, but they still physically exist and make and interact with magnetic fields). So for a coilgun, you directly get the impulse on the projectile being the impulse on the gun in an obvious way.		[[File:Comparison_of_the_recoil_of_conventional_and_electromagnetic_cannon.jpg\|thumb\|A comparison of the recoil impulse from a powder gun (green), electromagnetic gun (red), and a powder gun with a muzzle brake (blue) for a constant-energy launch (varying the mass of the projectile with speed to keep the total kinetic energy constant). Data from <ref>Edward M. Schmidt, "Comparison of the recoil of conventional and electromagnetic cannon", Shock and Vibration 8 (2001) 141–145 https://doi.org/10.1155/2001/590948</ref>]]An [[Electromagnetic_guns\| electromagnetic launcher]] is a device that uses electromagnetic fields and electric currents to push or pull a projectile. For a coilgun, the recoil is straightfoward - the fields of the projectile while it is being accelerated push or pull on the currents in the coils the same amount that the fields from the coils push or pull on the currents in the projectile (for a magnetic projectile, these can be the net currents you get by aligning the spins and angular momenta of the electrons around the atoms in the magnet - they're not the sort of currents that can be measured by a multi-meter, but they still physically exist and make and interact with magnetic fields). So for a coilgun, you directly get the impulse on the projectile being the impulse on the gun in an obvious way.

	For railguns, the situation is a bit more complicated. The magnetic forces in the railgun push the rails apart, not backward. So the impulse on the projectile is not countered by the impulse on the rails. Instead, the railgun is pushed back where the circuit is closed at the back end of the rails. Where the current completes the circuit in the driving generators and electronics (and power couplings if the generation is kept distant from the rails) is where the recoil is generated, from the same sort of action of the magnetic field on the current that also propels the bullet down the rails.		For railguns, the situation is a bit more complicated. The magnetic forces in the railgun push the rails apart, not backward. So the impulse on the projectile is not countered by the impulse on the rails. Instead, the railgun is pushed back where the circuit is closed at the back end of the rails. Where the current completes the circuit in the driving generators and electronics (and power couplings if the generation is kept distant from the rails) is where the recoil is generated, from the same sort of action of the magnetic field on the current that also propels the bullet down the rails.

Lwcamp: /* Effects of Recoil */

2025-04-09T14:33:17Z

Effects of Recoil

← Older revision		Revision as of 07:33, 9 April 2025
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	Recoil has a number of drawbacks. If you don’t have experience shooting and you are holding the gun wrong, it can knock you off balance. If you are shooting really big bullets going really fast, the gun recoiling can hurt or even leave bruises, especially if you are a small framed person. Many shooters start to subconsciously anticipate the kick, and flinch as they pull the trigger which will throw off aim. Most seriously, perhaps, is that when you are shooting rapid fire the recoil makes it hard to control the gun. On fully automatic fire, after the first two or three bullets the rapid recoil usually torques the barrel of the gun up into the air so all you are shooting at is the sky. And for really big guns, like cannons, you need to engineer in shock absorbers so the recoil doesn’t damage the cannon’s mount or throw off the aim of subsequent shots.		Recoil has a number of drawbacks. If you don’t have experience shooting and you are holding the gun wrong, it can knock you off balance. If you are shooting really big bullets going really fast, the gun recoiling can hurt or even leave bruises, especially if you are a small framed person. Many shooters start to subconsciously anticipate the kick, and flinch as they pull the trigger which will throw off aim. Most seriously, perhaps, is that when you are shooting rapid fire the recoil makes it hard to control the gun. On fully automatic fire, after the first two or three bullets the rapid recoil usually torques the barrel of the gun up into the air so all you are shooting at is the sky. And for really big guns, like cannons, you need to engineer in shock absorbers so the recoil doesn’t damage the cannon’s mount or throw off the aim of subsequent shots.

	The total recoil impulse will be the mass of the stuff that is launched out the end of the barrel times the speed of the projectile as it is launched. In math-speak, the recoil impulse will be <~~math~~>~~-\vec{~~p}</~~math~~>, where <~~math~~>~~\vec{~~p} = m ~~\, \vec{~~v}</~~math~~> is the momentum of the projectile with ~~<math>~~m~~</math>~~ the projectile mass and <~~math~~>~~\vec{~~v}</~~math~~> the projectile velocity. Here, the "projectile" is assumed to be the bullet (or shell or payload or whatever) in addition to any sabot or propellant gases or whatever else is shot out the muzzle of the gun.		The total recoil impulse will be the mass of the stuff that is launched out the end of the barrel times the speed of the projectile as it is launched. In math-speak, the recoil impulse will be -<b>p</b>, where <b>p</b> = m <b>v</b> is the momentum of the projectile with m the projectile mass and <b>v</b> the projectile velocity. Here, the "projectile" is assumed to be the bullet (or shell or payload or whatever) in addition to any sabot or propellant gases or whatever else is shot out the muzzle of the gun.

	The usual expression for the kinetic energy is ~~<math>~~K = ~~1/2 \,~~ m \, v~~^2</math>~~. Using <~~math~~>~~\vec{~~p}=m ~~\, \vec{~~v}</~~math~~> for the momentum we can express the kinetic energy as ~~<math>~~K = ~~1/2 \, \vec{p} \cdot \vec{v} =~~ p \, v~~/2</math>~~. This shows that for constant kinetic energy, the magnitude of the recoil impulse is ~~<math>~~p = 2 \, K / v~~</math>~~. So the faster the projectile is launched, the less recoil impulse will be produced (however, we must caution that the terminal effects of the projectile depend on more than just kinetic energy and it is a mistake to think that two projectiles with the same ~~<math>~~K~~</math>~~ but different ~~<math>~~m~~</math>~~ and ~~<math>~~v~~</math>~~ will have the same effect on target).		The usual expression for the kinetic energy is K = ½ m v². Using <b>p</b> =m <b>v</b> for the momentum we can express the kinetic energy as K = ½ p v. This shows that for constant kinetic energy, the magnitude of the recoil impulse is p = 2 K / v. So the faster the projectile is launched, the less recoil impulse will be produced (however, we must caution that the terminal effects of the projectile depend on more than just kinetic energy and it is a mistake to think that two projectiles with the same K but different m and v will have the same effect on target).

	The gun may gain the same recoil impulse as its projectile, but its recoil <i>energy</i> is much less. For a gun of mass ~~<math>~~M~~</math>~~ recoiling with impulse ~~<math>~~p~~</math>~~, its energy will be ~~<math>~~p^2 / (2 M)~~</math>~~. You can see that the heavier the gun, the less energy it will have on recoil. This is one of the reasons that shooting a heavy gun feels like it has less recoil than a light gun with the same cartridge, and why heavy guns are less likely to leave bruises. Holding a gun snugly effectively increases the gun's mass, helping to reduce the felt recoil. The impulse that throws off subsequent shots during rapid fire may be the same, but it will hit your shoulder less hard.		The gun may gain the same recoil impulse as its projectile, but its recoil <i>energy</i> is much less. For a gun of mass M recoiling with impulse magnitude p, its energy will be p² / (2 M). You can see that the heavier the gun, the less energy it will have on recoil. This is one of the reasons that shooting a heavy gun feels like it has less recoil than a light gun with the same cartridge, and why heavy guns are less likely to leave bruises. Holding a gun snugly effectively increases the gun's mass, helping to reduce the felt recoil. The impulse that throws off subsequent shots during rapid fire may be the same, but it will hit your shoulder less hard.

	==Recoil for Conventional Guns==		==Recoil for Conventional Guns==

Lwcamp: /* Effects of Recoil */

2025-03-09T21:14:50Z

Effects of Recoil

← Older revision		Revision as of 14:14, 9 March 2025
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	Recoil has a number of drawbacks. If you don’t have experience shooting and you are holding the gun wrong, it can knock you off balance. If you are shooting really big bullets going really fast, the gun recoiling can hurt or even leave bruises, especially if you are a small framed person. Many shooters start to subconsciously anticipate the kick, and flinch as they pull the trigger which will throw off aim. Most seriously, perhaps, is that when you are shooting rapid fire the recoil makes it hard to control the gun. On fully automatic fire, after the first two or three bullets the rapid recoil usually torques the barrel of the gun up into the air so all you are shooting at is the sky. And for really big guns, like cannons, you need to engineer in shock absorbers so the recoil doesn’t damage the cannon’s mount or throw off the aim of subsequent shots.		Recoil has a number of drawbacks. If you don’t have experience shooting and you are holding the gun wrong, it can knock you off balance. If you are shooting really big bullets going really fast, the gun recoiling can hurt or even leave bruises, especially if you are a small framed person. Many shooters start to subconsciously anticipate the kick, and flinch as they pull the trigger which will throw off aim. Most seriously, perhaps, is that when you are shooting rapid fire the recoil makes it hard to control the gun. On fully automatic fire, after the first two or three bullets the rapid recoil usually torques the barrel of the gun up into the air so all you are shooting at is the sky. And for really big guns, like cannons, you need to engineer in shock absorbers so the recoil doesn’t damage the cannon’s mount or throw off the aim of subsequent shots.

			The total recoil impulse will be the mass of the stuff that is launched out the end of the barrel times the speed of the projectile as it is launched. In math-speak, the recoil impulse will be <math>-\vec{p}</math>, where <math>\vec{p} = m \, \vec{v}</math> is the momentum of the projectile with <math>m</math> the projectile mass and <math>\vec{v}</math> the projectile velocity. Here, the "projectile" is assumed to be the bullet (or shell or payload or whatever) in addition to any sabot or propellant gases or whatever else is shot out the muzzle of the gun.

			The usual expression for the kinetic energy is <math>K = 1/2 \, m \, v^2</math>. Using <math>\vec{p}=m \, \vec{v}</math> for the momentum we can express the kinetic energy as <math>K = 1/2 \, \vec{p} \cdot \vec{v} = p \, v/2</math>. This shows that for constant kinetic energy, the magnitude of the recoil impulse is <math>p = 2 \, K / v</math>. So the faster the projectile is launched, the less recoil impulse will be produced (however, we must caution that the terminal effects of the projectile depend on more than just kinetic energy and it is a mistake to think that two projectiles with the same <math>K</math> but different <math>m</math> and <math>v</math> will have the same effect on target).

			The gun may gain the same recoil impulse as its projectile, but its recoil <i>energy</i> is much less. For a gun of mass <math>M</math> recoiling with impulse <math>p</math>, its energy will be <math>p^2 / (2 M)</math>. You can see that the heavier the gun, the less energy it will have on recoil. This is one of the reasons that shooting a heavy gun feels like it has less recoil than a light gun with the same cartridge, and why heavy guns are less likely to leave bruises. Holding a gun snugly effectively increases the gun's mass, helping to reduce the felt recoil. The impulse that throws off subsequent shots during rapid fire may be the same, but it will hit your shoulder less hard.

	==Recoil for Conventional Guns==		==Recoil for Conventional Guns==

Lwcamp: /* Credit */

2025-03-03T19:42:45Z

Credit

← Older revision		Revision as of 12:42, 3 March 2025
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	==Credit==		==Credit==

	~~Author~~: Phoenix, Tshhmon, and Luke Campbell.		Authors: Phoenix, Tshhmon, and Luke Campbell.

	[[Category:Military Technology]][[Category:Warfare]][[Category:Engineering‏‎]]		[[Category:Military Technology]][[Category:Warfare]][[Category:Engineering‏‎]]

Lwcamp: /* Credit */

2025-03-03T17:41:14Z

Credit

← Older revision		Revision as of 10:41, 3 March 2025
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	==Credit==		==Credit==

	Author: ~~Unknown initial author~~, ~~later expanded~~ and ~~edited by~~ Luke Campbell.		Author: Phoenix, Tshhmon, and Luke Campbell.

	[[Category:Military Technology]][[Category:Warfare]][[Category:Engineering‏‎]]		[[Category:Military Technology]][[Category:Warfare]][[Category:Engineering‏‎]]

Lwcamp at 17:39, 3 March 2025

2025-03-03T17:39:59Z

← Older revision		Revision as of 10:39, 3 March 2025
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	As mentioned for electromagnetic launchers, electromagnetic waves have a small amount of momentum. A [[Laser_Weapons\|laser weapon]] works by emitting a very high powered beam of electromagnetic waves. So lasers will produce a small amount of recoil. For most purposes, this recoil is completely negligible. The recoil force is the power of the beam divided by the speed of light. The recoil impulse is the energy of the beam divided by the speed of light. You would only get recoil impulses similar to that of a modern firearm if your laser was emitting as much energy per shot as the detonation of several tons of TNT.		As mentioned for electromagnetic launchers, electromagnetic waves have a small amount of momentum. A [[Laser_Weapons\|laser weapon]] works by emitting a very high powered beam of electromagnetic waves. So lasers will produce a small amount of recoil. For most purposes, this recoil is completely negligible. The recoil force is the power of the beam divided by the speed of light. The recoil impulse is the energy of the beam divided by the speed of light. You would only get recoil impulses similar to that of a modern firearm if your laser was emitting as much energy per shot as the detonation of several tons of TNT.

			==Recoil for Particle Beam Weaponries==

			Particle beams emitting relativistic particles are going to have recoil forces and impulses similar to that of a laser with the same power and energy per shot. While the particles they shoot do have mass so they will have a bit more recoil than a laser, for highly relativistic beams the recoil will be nearly the same. Even for moderately relativistic beams (with the total particle energy only a bit higher than the rest mass energy) the recoil will be not too much more than for light. It is only for sub-relativistic beams (with particle kinetic energies much less than the particle's mass energy) that recoil will start getting significantly more than that for a laser. And there's not much use for moderately relativistic or sub-relativistic beams as weapons.

	==Credit==		==Credit==

	Author: Unknown initial author, later expanded and edited by Luke Campbell.		Author: Unknown initial author, later expanded and edited by Luke Campbell.

	~~==Recoil for Particle Beam Weaponries==~~

	Particle beams emitting relativistic particles are going to have recoil forces and impulses similar to that of a laser with the same power and energy per shot. While the particles they shoot do have mass so they will have a bit more recoil than a laser, for highly relativistic beams the recoil will be nearly the same. Even for moderately relativistic beams (with the total particle energy only a bit higher than the rest mass energy) the recoil will be not too much more than for light. It is only for sub-relativistic beams (with particle kinetic energies much less than the particle's mass energy) that recoil will start getting significantly more than that for a laser. And there's not much use for moderately relativistic or sub-relativistic beams as weapons.

	[[Category:Military Technology]][[Category:Warfare]][[Category:Engineering‏‎]]		[[Category:Military Technology]][[Category:Warfare]][[Category:Engineering‏‎]]

Lwcamp: /* Recoil for Lasers */

2025-03-03T17:39:37Z

Recoil for Lasers

← Older revision		Revision as of 10:39, 3 March 2025
Line 45:		Line 45:

	As mentioned for electromagnetic launchers, electromagnetic waves have a small amount of momentum. A [[Laser_Weapons\|laser weapon]] works by emitting a very high powered beam of electromagnetic waves. So lasers will produce a small amount of recoil. For most purposes, this recoil is completely negligible. The recoil force is the power of the beam divided by the speed of light. The recoil impulse is the energy of the beam divided by the speed of light. You would only get recoil impulses similar to that of a modern firearm if your laser was emitting as much energy per shot as the detonation of several tons of TNT.		As mentioned for electromagnetic launchers, electromagnetic waves have a small amount of momentum. A [[Laser_Weapons\|laser weapon]] works by emitting a very high powered beam of electromagnetic waves. So lasers will produce a small amount of recoil. For most purposes, this recoil is completely negligible. The recoil force is the power of the beam divided by the speed of light. The recoil impulse is the energy of the beam divided by the speed of light. You would only get recoil impulses similar to that of a modern firearm if your laser was emitting as much energy per shot as the detonation of several tons of TNT.

			==Credit==

			Author: Unknown initial author, later expanded and edited by Luke Campbell.

	==Recoil for Particle Beam Weaponries==		==Recoil for Particle Beam Weaponries==

Lwcamp: /* Recoilless Guns */

2025-03-03T17:36:43Z

Recoilless Guns

← Older revision		Revision as of 10:36, 3 March 2025
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	Many shoulder-fired "rocket launchers" are actually recoilless guns.		Many shoulder-fired "rocket launchers" are actually recoilless guns.

			==Rockets==

			When a rocket launches, its high pressure propellant is allowed to vent out the back. The pressure pushes the rocket forward and the escaping propellant is pushed away by that same pressure, carrying away the impulse. As long as the jet of escaping propellant does not impinge on the launcher, the launcher itself will not experience any of the recoil. The jet of hot fast propellant gas does pose a hazard for things behind it, however. One method sometimes used to mitigate this is to pop the rocket out of the launch tube at low speed with a charge of cold compressed gas, and then only when it is a safe distance away does it light up its main motor. The initial low speed of the launch both reduces recoil forces and reduces the backblast danger from the initial launch.

	==Recoil for Electromagnetic Launchers==		==Recoil for Electromagnetic Launchers==