Pskov 1100 Gauss pistol

[DoNotRefill]

http://www.pskovinfo.ru/coilgun/indexe.htm

This wouldn't legally be a firearm in the US since it doesn't use gunpowder or anything similar. It's only shooting around 100 FPS now with a 25 second recharge period, but looks like it's got possibilities.

[TexasMexican]

1. Nifty

I'll wait for the rifles though. :P

[-..__...]

50. Plasma rifle in the 40 watt range.

Think of the savings on ammo!

[Frangible]

2. That's just cool

I can't see a practical use for it (yet), but, that's very geeky and cool.

[papau]

3. A build it yourself science project! - How did he gets specs - did he

build a prototype?


Coilgun weight is 1155 g powered by six AA NiCd accu placed in handle.
Bullet is iron, diameter is 5 mm, length 25 mm, weight is 2,75 g.
Muzzle velocity about 33 m/s. Destroy energy about 1,5 J.
DC/DC converter charging capacitors to 800V. Peak coil current is 400A.
Coilgun can do 50 fire shots without charging accu.
Time between shots is 25 sec. GUN MAKES NO SOUND WHEN SHOT.
Shot can shatter a glass bottle or pierce tin. Gun has 8 bullets placed in magazine.

[Wickerman]

4. Guess that would solve the Kentucky gun range noise issue

would make school shooting rampages less traumatic, too.

What is the point? Why would you want a silent gun? I thought folks liked the big "bang" sound.

[Superfly]

5. The bang gets old after a while...

Try dove hunting sometime. You can burn through 2 boxes of shells (50 shells total) in no time, which can really leave your head ringing. You can't wear plugs, because you need to communicate with your hunting partner to avoid accidents.

[Wickerman]

6. What?

that's what you get for killing those beautiful doves. :evilgrin:

[Superfly]

14. Correction...those beautiful *TASTY* doves.

pound for pound, the tastiest game bird in our skies.

[TX-RAT]

17. Quail the tastiest bird on the ground

[Maurkov]

22. Chukkar? (n/t)

[Superfly]

23. The hardest damned bird to hunt.

[Maurkov]

24. Which is why there's a question mark.

I've heard they are very good. :-(

[Something Blue]

34. Never hunted Chukar..

are they harder to hunt than grouse?

[Superfly]

35. Grouse are just mean....

Always pick a flight path so that they either

A) Put a tree between and you and them
B) Cause the barrel of your shotgun to thunk against a tree.

Chukar hunting involves a lot of hiking up and down canyon wlls like this one:

[Something Blue]

36. Yeah they're mean

The other favorite trick is to hold tight until you're about five feet past 'em then flush, causing you to discharge both your shotgun and your bowels at the same time!

Those are some impressive canyon walls!!!

[Superfly]

37. I've spent many days exploring the walls of the Snake R Canyon

Absolutely beautiful country.

[TX-RAT]

44. We released 125 Chukkars on our place 2 years ago.

Never hunt them and probably never will. Have hunted them in Calif and AZ.

[DoNotRefill]

7. The point is...

that once it's perfected, there's almost no recoil, theoretically there's almost no limit on velocity, the rate of fire (once the power supply problems are solved) would be adjustable from slow to blindingly fast, and there are all kinds of cool possibilities just in general.

[TX-RAT]

8. Almost no recoil?

How is that possible? If it could propel a 125g bullet to 1200fps wouldn't it have the same recoil as a 9mm?

[DoNotRefill]

9. Nope...

the major generating event of recoil is the explosion of the gunpowder. With a gauss gun, that doesn't happen. In effect, the bullet isn't propelled down the barrel, it's DRAGGED down the barrel by electromagnetic energy, which generates far less recoil.

[TX-RAT]

10. Propelled or dragged whats the difference?

Are we forgetting basic laws of physics? For every action there is a equal but opposite reaction.

[natasha1]

11. TX-Rat is correct

Since the weapon is discharging a known mass with a known force, there will be a recoil in the opposite direction.

What will likely feel much different, however, is the shock curve.

A traditional firearm works by creating an explosion up front, which propells the bullet down the barrel.

The electric coil continuously accellerates the projectile as it travels down the barrel.

Nat

[DoNotRefill]

28. Nope...

with gunpowder, combustion isn't intantaneous. This is what causes muzzle flash: powder exiting the barrel while still burning.

There are fast and slow burning powders. Generally, fast powders are used in shorter barrels, slower powders in longer barrels. Bullets continue to accelerate while going down the barrel as long as there's still gas generating combustion going on. It's only after the bullet leaves the barrel that the powder stops making it accelerate and resistance (both gravity and air pressure) starts to alter the trajectory.

[Something Blue]

30. B-b-b-but

What about where the force is coming from?

In the first case, the force (gas pressure) comes from behind the bullet, and so of course there is a force exerted back against the gun.

But if the bullet is indeed being dragged out of the gun, where is the backpressure against the gun? Look at it this way - if instead of a rail gun we attached a string to the front of the bullet and YANKED it out of the gun. Assuming no friction (which simplifies things), would there still be a recoil? Of course not.

I think there would be a force exerted on the firearm, but I don't think it would be recoil. If there is rifling involved (ok, I didn't read the article - is there rifling involved?) the projectile would impart a force on the barrel, but the force would be entirely rotational.

In other words - it might twist, but it won't push!

[TX-RAT]

43. Where will you attach the other end of the string?

[Something Blue]

56. Ah, shit

...you're right.

Newton wins after all.... :)

[DoNotRefill]

12. Right.

but an explosion creates much more force that needs to be counterbalanced than an electromagnetic implulse that would drive a projectile at the same speed.

Think about it...if what you're saying is true, things like maglev trains wouldn't work.

[TX-RAT]

13. How the force is generated doesn't matter.

Whether your driving a 2500lb electric car, or a 2500lb fuel burning car, it takes the same amount of force to drive 50mph.

[FeebMaster]

15. Look at it this way.

When you fire a gun, you're not only driving the bullet down the barrel but all of the gun powder as it's burning.

[natasha1]

16. Sort of irrelevant.

The pertinent equation is F=Ma, where F is Force, M is Mass, and A is acceleration.

The mass of the gunpowder is insignificant compared to the mass of the bullet.

So it takes a certain amount of force, F, to move a bullet of mass M to a given acceleration.

Newton's second law states that for every action there is an equal but opposite reaction. When you apply the force to the bullet, it pushes back. The reason why the bullet moves (a lot) and the gun moves but a little is because of the differences in mass. If the gun and bullet were of equal mass, they would move equally as fast in opposite directions.

Nat

[FeebMaster]

21. I don't know if I would call the mass of the gunpowder

insignificant compared to the mass of the bullet. It depends on the load I guess.

[DoNotRefill]

25. It's not the mass of the gunpowder that's important....

it's the volume of gas that is released when the gunpowder combusts.

Granulated powder releases more gas quicker than tubular powder does. And the finer the granules, the more power produced.

You can load three otherwise identical cartridges with 3 grains of powder each, one with tubular powder, one with a coarse granulated powder, and one with a finely granulated powder, and each will burn differently and produce different velocities.

If you unloaded a rifle cartridge that had been loaded with tubular powder, ground the strands of powder very finely, reloaded the cartridge, and then fired it, odds are excellent that the gun would explode due to the massive increase in pressure generated by the identical powder that's now in a different form.

[FeebMaster]

26. Good point.

I guess a muzzle break on a gauss gun would be pretty useless.

[DoNotRefill]

27. Maybe you could explain this, or maybe this will help you.

OK, when the powder in a cartridge is ignited, it produces a large volume of gas. The chamber and the barrel of the gun contain and directionalize the gas along the axis of the barrel. So, the bullet is pushed down the barrel, and an equal and opposite force is pushed into the breechface, causing the action to cycle. With me so far?

Now with a gauss gun, there's no expanding gas to push back on the breechface. The bullet is pulled, not pushed, down the barrel. So there's no force being expended backwards into the breechface, right? Unless ther's a vacuum generated by the passage of the bullet down the bore, which I suppose is possible, but that would be force pulling the gauss gun forward, not backwards.

With a standard gun, you've got mass (bullet), energy (propellant), mass (breechface). The energy is released between the masses, causing both objects to be pushed in opposite directions. With a gauss gun, you've got energy (magnetic), mass (bullet), mass (breechface). The energy pulls the first mass away from the second mass.

See the difference? If you've got two balls on the ground and are between them, and then push both balls at once, they'll both roll away in equal and opposite directions at the same time assuming you pushed in both directions equally, the mass of the balls are the same, and they meet the same resistance, right? If you've got two balls side by side, you're on one side, and you pull the first ball towards you, the second ball will stay still, right? You're not acting on the second ball.

[Maurkov]

31. Not exactly

At the same time the barrel is pulling on the projectile, the projectile is pulling on the barrel. As natasha1 mentioned, it will feel different, but the recoil is still there. It has to be, by Newton's third law.

In your example, you are the gun and the second ball doesn't matter. Try your experiment while wearing roller skates. Whether you push or pull on the ball, you both move and in opposite directions.

[DoNotRefill]

32. but percieved recoil....

is more a function of the slide recoilling.

If you push both balls while on roller skates, you'll stand still.

[Something Blue]

33. Well

I just put on rollerblades and pushed on both balls and all that happened was I fell down and groaned...

[DoNotRefill]

38. wrong balls...

:evilgrin:

[Something Blue]

41. Ooops...

Damn I HATE when that happens. Shoulda seen me at the table tennis tournament - boy was my face red! (Bring PING PONG balls?!? I thought you said KING KONG'S....ah, never mind...) :)

[DoNotRefill]

51. heh...

:)

[natasha1]

47. Nope, you still have recoil...

OK, when the powder in a cartridge is ignited, it produces a large volume of gas. The chamber and the barrel of the gun contain and directionalize the gas along the axis of the barrel. So, the bullet is pushed down the barrel, and an equal and opposite force is pushed into the breechface, causing the action to cycle. With me so far?

Yes, this is exactly correct so far.

Now with a gauss gun, there's no expanding gas to push back on the breechface. The bullet is pulled, not pushed, down the barrel. So there's no force being expended backwards into the breechface, right?

Here is where you go astray.

Yes, the bullet is indeed being pulled by electomagnetic forces. The question you are missing is - What is generating these forces, and what is the force being transferred to? Answer - the "barrel" of the gun - the electomagnetic rails (and then, of course, it is transfered onto the person holding the gun - recoil). The force being acted on the bullet is also being acted on the electomagnetic rails. The reason why the bullet moves much more than the rails do is because of the difference in mass. If the rails and the bullet were the same mass, then they would both travel in opposite directions with the same velocity.

Unless ther's a vacuum generated by the passage of the bullet down the bore, which I suppose is possible, but that would be force pulling the gauss gun forward, not backwards.

Actually, while not related to what is causing the recoil, this is a valid concern. If you do not have some means for air to fill the void behind the bullet as it travels down the barrel, the bullet would pull a vacuum behind it. In all likelyhood in fact, the bullet could not be removed from the barrel, without a tremendous force to overcome the vaccum. But this is an entirely different phenomenon, and is easily fixed by puttint a hole in the back of the barrel.

With a standard gun, you've got mass (bullet), energy (propellant), mass (breechface). The energy is released between the masses, causing both objects to be pushed in opposite directions.

Exactly so.

With a gauss gun, you've got energy (magnetic), mass (bullet), mass (breechface). The energy pulls the first mass away from the second mass.

But, again, you are neglecting what is doing the pulling. In this case, it is the electomagnetic rails, which generate a force on the bullet. Both get acted on equally by the force. The bullet moves a lot, and the rails only a little, because the rails are much more massive than the bullet.

If you've got two balls on the ground and are between them, and then push both balls at once, they'll both roll away in equal and opposite directions at the same time assuming you pushed in both directions equally, the mass of the balls are the same, and they meet the same resistance, right?

Yes, and, more importantly, you will not move at all, because as you generate an equal force against both balls in opposite directions, they both push back on you (the generator of the force) equally, and thus you go nowhere.

If you've got two balls side by side, you're on one side, and you pull the first ball towards you, the second ball will stay still, right? You're not acting on the second ball.

Yes, if you only push on one ball, only it moves but so do you, in the opposite direction. Depending on the differences of mass, one will move much more than the other. If you push a marble, it will move and you will hardly move at all. If it is a boulder, it may move imperceptibly, but you will knock yourself over.

Nat

[FeebMaster]

48. A vacuum behind the bullet shouldn't be a problem.

Although this is talking about rail guns and not coil guns like the Pskov 1100.

http://www.powerlabs.org/railgun.htm

If full power was to be applied to a static armature the rails and whatever was between them would instantaneously melt under the intense localized heat produced by Ohmic heating as 100thousand amperes tried to make it through the contact resistance. In order to prevent the Rail Gun from becoming a spot welder it is necessary that the armature be moving with some initial speed prior to electromagnetic acceleration. Most amateur designs fail because of lack of knowledge of this. In this design the armature is injected by a gas gun consisting of a 1000CC Schedule 80 PVC gas reservoir connected to a 30cm long barrel through a reducer that goes from 1/2"^2 to 1/4" x 0.6" through a 60 degree taper. A 1/2" diaphragm pilot operated solenoid valve controls the gas flow and essentially serves as the trigger for the gun. Approximately 5% of reservoir capacity is used in one shot. The system is designed for 500PSI (35ATM), enough to consistently fire a 6 gram aluminum slug out at 150m/s, or a Teflon slug at 195m/s (634.5fps, 696km/h, 432.6mph).


He's got some coil guns too:

http://www.powerlabs.org/gaussgun.htm
http://www.powerlabs.org/multistagecg.htm

[TX-RAT]

49. Does a rail gun actually have a breach?

[DoNotRefill]

52. Right.

OK, here's where the disconnect is.

With a standard firearm, there's a lot of energy produced which does not go to propel the bullet down the barrel. This is necessary to ensure reliable functioning of the weapon which is not involved with pushing the bullet down the barrel. That energy needs to be absorbed, and is felt as recoil when it's transferred to the shooter. With a guass gun, there's far less energy required to function the weapon, so far less energy is used. The ONLY energy used and felt is what propels the bullet. If you were to fire a gauss gun without a projectile, you'd feel nothing at all, since the energy would simply be electricity travelling through the coil. The electromagnetic field created wouldn't affect anything. Hence the smaller recoil.

[natasha1]

57. Well, yes...

With a standard firearm, there's a lot of energy produced which does not go to propel the bullet down the barrel. This is necessary to ensure reliable functioning of the weapon which is not involved with pushing the bullet down the barrel. That energy needs to be absorbed, and is felt as recoil when it's transferred to the shooter.

OK, we're talking two different things here.

First, yes, in a traditional auto-loading rifle, some of the recoil energy is used to cycle the action, and some of this energy is "lost" to heat. What forces are not dissapated through this action are still passed onto the shooter. In a frictionless system (which most physics problems like this are considered), any loading-action mechanism that works on recoil is not going to affect the total force of the the system (the gun) pointing backwards towards the shooter.

For example - the energy of the explosion that propelled the bullet pushes back on the breach. The bullet goes forward, the breach goes backwards. But what stops the breach? The gun frame. Thus all the energy imparted into the breach thus is imparted to the gun frame when the breech reaches the limit of its action. What about the spring that slams the breach back, you ask? Well, it is attached to the gun frame, too. So, except for friction, which is usually ignored, all of the energy put into the breach ultimately is transfered into the gun frame. If this were not so, the breach would continue moving backwards forever. It is stopped by something - the frame, which in turn is stopped, by the shooters hand - what we call "recoil".


With a guass gun, there's far less energy required to function the weapon, so far less energy is used. The ONLY energy used and felt is what propels the bullet.

To move a bullet to the same velocity over the same period of time takes the same amount of energy, whether that energy comes from electromagnetic forces or explosions of gunpowder. So both weapons will have very similar recoil. F=Ma. Both weapons want to move the same mass to the same acceleration, and so will impart the same force onto the mass. That force in turn will be pushed back with equal and opposite manner against the gun.


If you were to fire a gauss gun without a projectile, you'd feel nothing at all, since the energy would simply be electricity travelling through the coil. The electromagnetic field created wouldn't affect anything. Hence the smaller recoil.

The smaller recoil in this case is because mass=0 (zero), and so the equation becomes F=(0)*a, which means F=0. Obviously if no mass is being ejected from the system the force sum is zero. This is why when you fire a blank cartridge there is virtually no recoil, because there is no bullet. There is still some recoil because, in fact, the burning propellant does have some mass, and, being ejected at an extremely high acceleration, still creates some perceptable force.

On a related tangent, rocket engines function in the same way. They eject mass, at varrying velocities, and, since no one is holding onto the rocket, it flies away.

"traditional" rockets function by ejecting large amounts of mass (hydrogen and oxygen, for example) at relatively low (though supersonic) velocities, to generate a force, which moves the rocket.

New rocket engines, called "ion engines", function by ejecting small amounts of mass (atomic particles - plasma) at extremely high (relativistic - fractional light-speed) velocities. Even though the mass is small, the enormous acceleration imparted to the mass still makes for a force useful for propulsion in the vacuum of space.

Nat

[DoNotRefill]

63. I've fired a lot of crimped blanks...

and there's perceptably less recoil, but it's still there, even though there's no projectile launched. I suspect most of it comes from cycling the action. Or, the other possibility is that it effectively acts like a rocket motor, with the barrel acting as the exhaust tube.

[DoNotRefill]

39. Right, but....

the EXCESS force produced in a firearm becomes recoil. With a gauss gun, there's no excess force, merely very temporary magnetic attraction.

Additionally, with a gauss gun, there's no need for larger amounts of force necessary to cycle the action, extract and remove the spent cartridge, and chamber a new round. There's no case, there's no extraction process, and the magazine spring brings the next projectile into proper alignment, without the need to chamber the round, so your energy requirement is just to power the coil, not function the action. So there's less force required for the gun to function, which means less energy released, which means less energy transfer to the firer, which means less percieved recoil.

Think about your analogy with the car. Much energy in a fossil fuel car is wasted, in the form of things like heat, et cetera. It takes the same amount of force in one sense (the number of rotations through the transmission to make the wheels go at that speed) but the wasted force generated in a fossil fuel car is much greater than the wasted force in an electric car (which produces far less waste heat and other waste products), so while the energy/foot pounds of torque required to go the same speed may be the same, the TOTAL amount of energy involved with an electric car is far less than a comparable fossil fuel powered car. The main heat source in an electric car is friction, while it's combustion in a fossil fuel car.

[Hammie]

53. Yes but,

A conventional pistol imparts linear acceleration to the projectile, just like the EM gun. It also imparts rotational acceleration to the projectile by virtue of its rifled barrel and acceleration to the propellant gasses. In a pistol, the weight of the propellant might only be 5-10 grains but the velocity it achieves at the muzzle is quite a bit higher than that of the projectile. The acceleration force of the propellant gas cannot be neglected. It is common for diverters to be employed to redirect the propellant gas in particular directions that counteract the other recoil forces.

Since the EM gun doesn't have propellant gas and, probably, doesn't have a spin stabilized projectile, it certainly has lower recoil than a conventional pistol of the same weight firing a projectile of the same weight at the same muzzle velocity.

[natasha1]

58. Oops, you may be right...

A conventional pistol imparts linear acceleration to the projectile, just like the EM gun. It also imparts rotational acceleration to the projectile by virtue of its rifled barrel and acceleration to the propellant gasses.

Both of which forces are transferred to the gun, which stays still by virtue of being held still by the shooter (recoil).

In a pistol, the weight of the propellant might only be 5-10 grains but the velocity it achieves at the muzzle is quite a bit higher than that of the projectile. The acceleration force of the propellant gas cannot be neglected.

Oops, you are might be right. The force generated by the escaping high-velocity gas might indeed need to be considered. However, I'm having some trouble with it, as the gas velocity can't be any faster than the bullet while it is still in the gun, because the gasses can travel no faster than the bullet in front of it. Nonetheless, the high accleration of the gas, even with its low mass, might in fact contribute to a higher recoil.

Ah, I have it now. In effect, any difference in recoil force should differ only by the mass of the powder times the acceleration of that same powder. In effect, for the traditional gun, it will be:

F = ( Mass(bullet) + Mass(powder) ) * Acceleration

While in the gauss gun it will be:

F = ( (Mass(bullet) * Acceleration

It is common for diverters to be employed to redirect the propellant gas in particular directions that counteract the other recoil forces.

True, true.

Since the EM gun doesn't have propellant gas and, probably, doesn't have a spin stabilized projectile, it certainly has lower recoil than a conventional pistol of the same weight firing a projectile of the same weight at the same muzzle velocity.

The spin stabilization shouldn't have much to do with recoil - linear forces. It just means that a gauss gun won't have any torsional forces applied to it like a traditional gun does.

But, due to the smaller amount of mass being ejected (no propellant), it should have a slightly smaller amount of recoil. Of course, having no propellant, it cannot employ diverters to help reduce any of the recoil.

Nat

[Wickerman]

18. cool, you could take the life of so much more "stuff" so much more

quickly. And all silently.

:scared: You guys are starting to scare me.:scared:

[TX-RAT]

19. If the projectile breaks the sound barrier its not silent

OK I'm done, just had to throw that in. Sorry didn't mean to scare.

[Wickerman]

20. great

just fucking great. :P

[DoNotRefill]

40. If you don't mind me asking....

and I don't mean to insult you in any way, but what, exactly, did you do to screw your karma so badly in your last life that in this life you ended up moderating down here?

I'd think that serving a few thousand years in purgatory would have been a better option to expiate your sins than getting stuck with this job.

Of course, I'm still glad you're here...we sinners, in this life or the previous one, gotta stick together... ;)

[DoNotRefill]

29. Isn't that a result of being in the Gungeon?

I like driving cars really fast. That doesn't mean I like killing people by running them over.

Enjoying shooting doesn't necessarily mean you enjoy killing. If it did, "plinking" would be pretty boring. After all, how can you kill a can of soda? That's my favorite reactive target. You get fun reactivity, and cleanup is simple.

[Wickerman]

42. I hope you recycle after you have murdered

that can. :grr:

[FrontPorchPhilosophr]

45. Exotic Weapons

Anyone remember the MBA Gyro-jet pistol from the '70's? :think:

[OpSomBlood]

46. Designed for space combat.

Today, the ammo goes for about $35 a round.

[DoNotRefill]

54. Murdered cans?

Oh, christ....what's next, giving cans the vote??? How would they pull the lever?

DNR, can-murderer extraordinaire

:evilgrin:

[Hammie]

55. I wouldn't start to worry yet

It apparently fires a 42 grain projectile at a stately 100 ft/sec. By contrast, a .22 long rifle pistol will launch the same weight projectile (roughly) in the neighborhood of 1,000 ft/sec. Any weapon that discharged a projectile at such a liesurely pace would be just as quiet.

[MrSandman]

59. Here is the udated prototype...

[WhiskeyTangoFoxtrot]

60. I can develop more energy with a baseball

Yup. I can toss a baseball, which weighs a hell of a lot more than 42 grains right around 100 feet per second. It's pretty quiet too!

[Something Blue]

61. True, but

by how many orders of magnitude does your current technology have the potential to improve? ;)

[WhiskeyTangoFoxtrot]

62. True

Considering I can't hit the broad side of a barn from the inside, there is a little room for improvement. You're right though, not a whole lot.

[7th_Sephiroth]

64. interesting

but i have built a railgun that fires 12 rounds in 12 seconds, runs off a cell phone battery

[GregW]

65. How about a system that fire 40mm grenades at 240,000 RPM?

(Using inductive firing)

http://www.metalstorm.com/04_video_live_firings.html