Semi-OT: Do Gauss Rifles Kick?

[pmulcahy11b]

I call this thread "semi-OT" because in 30-50 years time or so, gauss rifles may be a standard infantry weapon...

For those who have never been able to play Traveller, a gauss rifle is a personal-sized electromagnetic railgun. My question is: would a gauss rifle kick? If so, would it kick less or more than a similar-caliber rifle of today? Would a recoil dampener be easier to make for a gauss rifle?

[headquarters]

all my technological insight on this comes from RPG lit.,so I amnot really sure and so on and so on..but!

I venture : no.

It accelerates its projectile through magnetic fields that only excert energy one way -and friction between weapon and projectile is zilch.

( I think)

[Adm.Lee]

I thought that was half of the point of making a gauss gun-- no recoil, and really high muzzle velocity?

[StainlessSteelCynic]

As far as I have been able to understand the technical information it's as Headquarters mentioned, they don't produce recoil because they don't have any explosive force to counteract.

[Legbreaker]

What about inertia?
Of course there would be recoil, it's just unlikely to be a big factor.

Just remember that "for every action" ie the projectile moving forward, "there is a equal and opposite reaction" ie recoil.

[StainlessSteelCynic]

Actually I've made a big mistake, confusing railguns with gauss guns. The two work on different principles and I really need to find a site with a simpler explanation of the two
Gauss guns, also called coilguns do display a recoil comparable to modern firearms according to this site http://www.orbitalvector.com/Tactica...s/COILGUNS.htm

[kato13]

Due to conservation of momentum any weapon that fires a projective is going to have some recoil based on the mass of the projectile and how fast it leaves the barrel. If the (similar mass) projectiles leave the barrel at the same velocity the force generated backwards should be the same. However I am not sure that an equal force would result in a totally equal "recoil". I am assuming that a Gauss projectile would have more even acceleration when compared with a chemical projectile. This might reduce the high end force felt at any particular moment during the projectile's acceleration phase and there fore might reduce the apparent recoil.

[Legbreaker]

The force applied would be equal in both directions, however the much greater mass of the weapon over the projectile will minimise the amount actually felt by the firer.

[kato13]

Was thinking about this more. Technically the mass of the propellant would also need to considered, given that a majority of it also leaves the barrel at a significant velocity. So chemical propelled weapons would have a larger rearward force.

[StainlessSteelCynic]

A problem comes about with larger weapons (i.e. multiple coils) because the opposition forces are not necessarily directed backwards and the energy is applied sequentially.
The weapon sends the projectile out of the barrel by the force of magnetic attraction first (drawing the projectile towards the coil) and then magnetic repulsion after (pushing the projectile away from the coil after it has passed through the coil).
Each individual application of energy only generates a small recoil force but there's a number of them running in sequence. I really do not understand much about the way the magnetic force works and what sort of effect it has regarding recoil so for the more technically proficient, you should probably google for a better explanation than mine

[Legbreaker]

My thoughts are that the projectile is not actually kicked out the barrel by a single event but accellerated by the coils (or whatever).
Therefore, while there will still be a felt recoil, it will not be so jarring to the firer as with conventional propellants (but would still be applied in a fraction of a second).

[Targan]

Originally Posted by Legbreaker

What about inertia? Of course there would be recoil, it's just unlikely to be a big factor. Just remember that "for every action" ie the projectile moving forward, "there is a equal and opposite reaction" ie recoil.

Originally Posted by kato13

Due to conservation of momentum any weapon that fires a projective is going to have some recoil based on the mass of the projectile and how fast it leaves the barrel.

I'm really glad someone pointed this out. Of course there would be recoil! Probably not as much as with a chemical propellant weapon, but it will still be there. Every action has an equal and opposite reaction. One difference between the two different types of projectile weapon that springs to mind is that the projectile in a conventional firearm is accelerated the most at the moment of propellant ignition, then acceleration drops off sharply as the bullet moves down the barrel. In a railgun the acceleration of the projectile remains roughly constant until it exits the barrel.

[pmulcahy11b]

So the recoil would be more of a push on the shoulder instead of one kick. Would automatic fire simply result in a longer push?

[Legbreaker]

Accuracy might increase as you're unlikely to need a great big bolt, etc as you do in the M60 banging back and forth inside. I'd imagine the only working parts would be those moving the new round into position for firing.
The whole weapon could probably be lighter than conventional weapons that need to account for the rapidly expanding gases and extremely high internal pressures, and this could actually have a detrimental effect on recoil - less mass to soak up the recoil.

The time it would take for a single projectile to move from the "breach" to the muzzle isn't likely to be all that much longer than a conventional round - a small fraction of a second. However, it probably would be slow enough than the felt recoil would be more like a swift push than a sudden thump.

Firing cyclicly, I would imagine it would be a little like holding a hose and after the initial half second, be much easier to keep on target. It does depend a lot on the RPM of the weapon though - slow RPM would certainly result in "pulsing" while faster RPM would be much smoother (but chew through ammo and power).

[Targan]

Originally Posted by Legbreaker

Accuracy might increase as you're unlikely to need a great big bolt, etc as you do in the M60 banging back and forth inside. I'd imagine the only working parts would be those moving the new round into position for firing. The whole weapon could probably be lighter than conventional weapons that need to account for the rapidly expanding gases and extremely high internal pressures, and this could actually have a detrimental effect on recoil - less mass to soak up the recoil.

I wouldn't be surprised if one of the largest, if not the largest, part of such a weapon's mass would be its power pack. The designers of such a weapon would no doubt place the power pack in such a location on the weapon as to maximise the use of the power pack's mass to negate recoil as much as possible and balance the weapon. The power pack wouldn't get lighter as it is depleted, unlike a magazine or belt, and the projectile magazine would weigh very little compared to a magazine holding conventional bullets. So the weapon should stay balanced even as its power and ammunition is depleted.

Originally Posted by Legbreaker

The time it would take for a single projectile to move from the "breach" to the muzzle isn't likely to be all that much longer than a conventional round - a small fraction of a second. However, it probably would be slow enough than the felt recoil would be more like a swift push than a sudden thump.

Firing cyclicly, I would imagine it would be a little like holding a hose and after the initial half second, be much easier to keep on target. It does depend a lot on the RPM of the weapon though - slow RPM would certainly result in "pulsing" while faster RPM would be much smoother (but chew through ammo and power).

Most concept gauss rifle plans I have seen use very small, very high velocity flechettes. Each round weighs much less than most RL bullets. The rate of fire for a gauss rifle could theoretically be incredibly high, especially as the very small diameter and mass of each round naturally lends itsself to a high ROF.

[kato13]

Originally Posted by Targan

I wouldn't be surprised if one of the largest, if not the largest, part of such a weapon's mass would be its power pack.

Guns, Guns, Guns theory on this is that Gauss weapons would not be the equal to propellant weapons (in term of cost, power, etc) until room temp superconductors were invented for power storage. Vehicle based weapons and niche anti material weapons could be practical before then however.

Also using their system, lasers would be generally superior in terms of damage (but not in flexibility) over Gauss weapons. This is due to the fact that a laser's firing chamber can be folded (allowing more power in a smaller weapon) and a Gauss weapon's cannot.

[Legbreaker]

Here's a thought - include the power source with each round of ammo.
Ammunition is supplied in prepacked magazines and each two part round has just enough power to propell the projectile, or the actual magazine is the power pack....

Yes, definately needs a huge advance in technology, but could be something to think about.

[kato13]

Originally Posted by Legbreaker

Here's a thought - include the power source with each round of ammo.
Ammunition is supplied in prepacked magazines and each two part round has just enough power to propell the projectile, or the actual magazine is the power pack....

Yes, definately needs a huge advance in technology, but could be something to think about.

Guns^3 and the Expansion More Guns^3 have rules for these. Another neat thing about Gauss weapons is that you can dial up or down the power depending on the situation. Useful for subsonic, additional range, and to prevent over penetration.

[headquarters]

recoil acknowledged.

http://74.125.77.132/search?q=cache:...&hl=no&ct=clnk

someone said something about lasers being superior - I just thought I would mention that "pluming" seems to be a dealbreaker with these.I.e the target starts vaporizing at POI and the vapour disperse the beam and lessens effect .
A Gauss gun might be more practical for an infantry portable weapon..

superguns thread Kato ?

bz-zapp!

[Legbreaker]

Originally Posted by headquarters

I just thought I would mention that "pluming" seems to be a dealbreaker with these.I.e the target starts vaporizing at POI and the vapour disperse the beam and lessens effect.

How dare you bring actual science into this!!?


Oh, wait. That was me...

[Targan]

Originally Posted by kato13

Guns^3 and the Expansion More Guns^3 have rules for these. Another neat thing about Gauss weapons is that you can dial up or down the power depending on the situation. Useful for subsonic, additional range, and to prevent over penetration.

Hmm, "More Guns, Guns, Guns". I might have to get that. I've been using 3G for years, including for all of my Gunmaster conversions.

[kato13]

Originally Posted by headquarters

someone said something about lasers being superior - I just thought I would mention that "pluming" seems to be a dealbreaker with these.I.e the target starts vaporizing at POI and the vapour disperse the beam and lessens effect .
A Gauss gun might be more practical for an infantry portable weapon..

superguns thread Kato ?

bz-zapp!

Blooming is a problem but given the 'instant' rate of transmission of energy lasers have found success in the Boeing YAL-1.

I have zero objections to such a thread, but an "OT-" is probably merited.

Originally Posted by Targan

Hmm, "More Guns, Guns, Guns". I might have to get that. I've been using 3G for years, including for all of my Gunmaster conversions.

My More 3G is one of my only RPG books that has never been put into storage for any period of time. It comes from the same publishers of Timelords and Corps which make up the base of my custom gaming system.

[pmulcahy11b]

Originally Posted by Legbreaker

...or the actual magazine is the power pack....

That's how I've heard that most such proposals would work.

[Legbreaker]

Ignoring battery size and weight for the moment, how much power is required to propel a slug of say 10 grams?

[kato13]

Originally Posted by Legbreaker

Ignoring battery size and weight for the moment, how much power is required to propel a slug of say 10 grams?

It is kinda complicated but 3G handles it well IMO

From 3G
Below are the final muzzle energies of certain rounds and how fast that muzzle energy would propel a 10g projectile.
200 J (.22) - 201 m/s
400 J (.38 Special) - 284 m/s
600 J (9 mm) - 347 m/s
1000 J (.357 Mag) - 448 m/s
1400 J (.44 Mag) - 531 m/s
1800 J (5.56mm) - 602m/s
3500 J (7.62mm) - 839m/s

The tech level of the weapon then determines the transfer ratio from battery -> capacitor -> accelerator

We are at the begining of TL12 which requires 1600 J Battery -> 400 J Capacitor -> 100 J Muzzle energy

Capacitors of 2.0 J/g are the limiting factor at the moment (batteries can have 1100 J/g) for multishot or powerful weapons. Room temp Super conductors will change everything as they can store 125 J/g.