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View Full Version : Twenty-three pound projectile at 7800 F.P.S.



Phineas Bluster
02-22-2015, 01:06 AM
Deleted

coloraydo
02-22-2015, 04:17 AM
Navy quoted (about 5300 mph or 7800 fps)

Slight correction, 5300 mph comes out to 19,080,000 fps. Pretty impressive.

JB Weld
02-22-2015, 04:40 AM
I read about this the other day. It has an impressive rate of fire as well.
I cannot remember the actual #, but they can send several of those shells downrange quick, fast, and in a hurry!

Duckiller
02-22-2015, 05:54 AM
5300mi/hrx5280ft/mixihr/3600=7773 fps or approx 7800fps. 19080000 is feet per hour.

texaswoodworker
02-22-2015, 06:36 AM
I wonder how well it groups. Is it sub MOA? :p

garym1a2
02-22-2015, 09:03 AM
But can it hit a target and be more effective than a savo of guided missiles?

bikerbeans
02-22-2015, 09:09 AM
If Ackley was around today I bet he would try an improve this gun.

BB

Plate plinker
02-22-2015, 09:13 AM
I volunteer to have one installed on my front yard. I could shell GARY IN and maybe parts of Chicago.

fng
02-22-2015, 09:24 AM
oh the new 16,100,000gr boolit

Ballistics in Scotland
02-22-2015, 09:42 AM
But can it hit a target and be more effective than a savo of guided missiles?

That, really, is the problem. BAe have been working on this for many years, and it has great advantages besides velocity. It doesn't heat up (er... I think), and I am sure it doesn't heat up enough to erode. I would guess that it is much lighter than a gun of comparable performance, though it might be very long. I think it would avoid the blast signature on dust, vegetation etc. by which conventional artject to illery is detected. I don't know whether a sonic crack makes sound location possible, but I would doubt it. But I can't imagine that the projectile is stabilized by rifling, and anything fin-stabilized loses quite a bit of velocity by extra friction.

I was taught on a summer course in 1970 by a delightful Parisian lady who was born with the century, and liked Paris better with the horses. She claimed her father had escaped execution by the Communards of the 1871 revolt because his hobby of rowing on the Seine had given him working-class callouses. Well I don't doubt he had a worrying experience, but the government forces executed far more people than the Commune. She said people had nothing but contempt for the German Paris gun, because it could hit nothing much smaller than a city. There never was any evidence that it could pick out targets, although it surely used the best technology of a war in which artillery came closer than any other arm to modern capability.

Dr. Gerald Bull of Iraqi supergun fame wrote the ultimate book on the Paris gun. But it seems invariably to be priced at around $300 on the used market, and he has gone where he can't promote a new edition.

If the rail gun gets its range (around 50% greater than the Paris gun's) by the same method, angling ar greater than the theoretical maximum elevation to take advantage of thinner air), it will surely be subject to some of the same limitations. We don't know a lot more about drift, for which even conventional heavy artillery of the period was used to calculating. We can certainly calculate almost instantaneously by computer, but just what the air is doing up there may be hard to determine.

The mechanical calculating devices used in large warships were far better than most of us today realize. People using instruments in different parts of the ship could enter in almost all the factors which affect the shell's flight, such as movement, wind, humidity, air temperature, direction on the compass, temperature and wear of the gun etc. "Warspite" and "Scharnhorst" both made first-shot hits at 26,000 yards, with both vessels moving. But that means visible on the horizon, and 223,000 yards isn't. I think use of that long range has to depend on coordination with radar observation from somewhere else.

Vanished weapons come back sometimes, like muzzle-loading mortars and the hand-grenade. At the very least the existence of such weapons, even smaller ones at closer range, mean we are unlikely ever to see armoured warships again.

BrassMagnet
02-22-2015, 11:27 AM
But can it hit a target and be more effective than a savo of guided missiles?

My Specialty was Firecontrol Radar. A Salvo of missiles can be intercepted, deceived, or jammed. A series of steel containers full of explosives weighing in like a large vehicle can be pushed a little off target when it is successfully intercepted near the target. It cannot be deceived or jammed.

Hello!
This is the US Navy knocking on your door!
Soon we will be knocking on your basement door.
How do you like us now?

Blammer
02-22-2015, 11:32 AM
I'm betting the 23 pound projectile is cheaper than the guided missile.

theperfessor
02-22-2015, 11:37 AM
Any reason that end-guidance technology can't be incorporated into the projectile? The Navy was awfully quick to integrate proximity fuses when they were developed into existing artillery.

WILCO
02-22-2015, 12:03 PM
Anyone else notice the bridge, oil tanks and power plant in the background of the test footage?

Ballistics in Scotland
02-22-2015, 12:11 PM
My Specialty was Firecontrol Radar. A Salvo of missiles can be intercepted, deceived, or jammed. A series of steel containers full of explosives weighing in like a large vehicle can be pushed a little off target when it is successfully intercepted near the target. It cannot be deceived or jammed.

Hello!
This is the US Navy knocking on your door!
Soon we will be knocking on your basement door.
How do you like us now?

It would be interesting to know, if it is fit for the public domain, whether fire control radar can now operate accurately beyond the horizon. My guess would be only if the signal comes from an aircraft or small vessel much closer up, possibly relayed by satellite. GPS would now give a very accurate position for the radar itself.

The picture is one of my favourite pieces of ordnance, the hundred-ton Armstrong muzzle-loader rifled gun in Gibraltar. Whenever I pay it a visit I reflect that it could be fatal to any modern vessel, except probably one of Ronald Reagan's demothballed battleships, and nobody can jam the guidance system. In the 1890s they realized that it had never been fired in anger, or often in much of anything, so it was about time they did. It failed to go off, so a particularly thin soldier had to go headfirst down the barrel clutching a ringbolt, for which he was promoted to corporal.

Lots of things can be intercepted now which couldn't in the past, probably including artillery shells. I don't much fancy anybody's chances of hitting a major power's warship with an Exocet nowadays. But the size and speed of this thing would surely make it a far more difficult target.

As to built-in guidance, it would depend on how you knew where to guide it. I suppose a camera is possible, since one of the major snags with delicate equipment is spin, which it probably won't have. Now there would be a filmclip you'd have no trouble getting on the news.131673

leebuilder
02-22-2015, 12:20 PM
Thats crazy. I did notice all the stuctures in the back ground. I am wondering where all the muzzle flash is coming from?

BrassMagnet
02-22-2015, 12:29 PM
A 16" shell weighs like a large vehicle.
At 23# this is much smaller.
Once a 23# version is fielded, larger projectile models will be developed.
Radar is used to detect, track, and target airborne targets.
Ground targets are detected by recon aircraft and satellites more often than not. The detection does not have to be recent. Think Google Earth. The real issue is target analysis! Is that an underground hospital or a Command and Control bunker or missile silo? Five year old Google Earth photos could tell.

.30-06 fan
02-22-2015, 12:31 PM
If Ackley was around today I bet he would try an improve this gun.

BB

awesome

Artful
02-22-2015, 12:38 PM
Thats crazy. I did notice all the stuctures in the back ground. I am wondering where all the muzzle flash is coming from?

Same as when space ship reenters - friction of the air compressing and moving out of the way. Think Diesel engine.
http://www.geek.com/wp-content/uploads/2013/07/fireball-header-590x330.jpg

NavyVet1959
02-22-2015, 12:45 PM
It's main advantages are economics and shipboard safety. Cheaper projectiles, no propellant or explosives that could burn or explode. At that speed, it would not take much in the way of directional fins to fine tune the impact point.

kodiak1
02-22-2015, 12:56 PM
110 miles! I am going to have to get a better scope that will allow for the curvature of the earth so I can see my target.....
What grain of projectile for deer?
That is fricking amazing and mind blowing.

MtGun44
02-22-2015, 01:17 PM
I would expect that the intent is more for 10-20 mile usage where velocity would still be
very high so a solid steel or depleted uranium projectile would have huge kinetic energy
and penetration. Also, if engaging a target at 5 miles, the time of flight is going to
be only in the 4-5 second range, very fast and impossible to intercept or defend
against.

An easy way to remember the mph to ft per second conversion, at least for me, is to
remember that 60 mph = 88 fps. Ft per sec are very roughly 50% greater than mph,
just as a quick mental check on whether you got it right doing the conversion.

leebuilder
02-22-2015, 01:31 PM
Thanks Artful. Still cant wrap my head around it, that is some power.
being in the Navy for 22 years i see how it will solve alot of storage issues. Long gone are the days of the big warships.
had the privlage of working with a guy that worked with Dr. Bull, "14 minute flight time for some tests of projectiles and propellants".
Wow
wow,,, say that again, wow.

GabbyM
02-22-2015, 01:36 PM
Any reason that end-guidance technology can't be incorporated into the projectile? The Navy was awfully quick to integrate proximity fuses when they were developed into existing artillery.

I'd think acceleration G forces would destroy any electronics. The Navy 5" x 54 smooth bore gun first put to sea on the USS Winston Churchill. Has a similar range with full weight five inch shell. It fires the shell out of the Troposphere then it skips along the barrier layer just like the WWI Paris Gun. Electronics guides shell to target after it re enters. New Zumwalt class Navy ships have six inch guns (155mm) but we are only building two so far.

This rail gun would have the firepower to engage mass attacks by drones. Waves of suicide boats or whatever. I know the auto plant up in Bloomington can build one thousand cars every 24 hours when in full production. Tool that up to make drone aircraft or boats then run it for a couple months. Our enemies build cars too! I'd say the navy needs a rapid fire gun with a whole lot of storable ammo. What I read on the rail gun is in direct fire to the horizon. They have plenty of remaining velocity to kinetically take out targets. You really do not want a big explosion as the blast blinds your radar in that area for a moment. Enemies know this also and will gorilla line cruise missiles at you. Our Aegis Combat System could help here with radar and other tracking assets offset from the targeted ship.

One thing that is obvious. WWII tech will not win any modern wars. Plus we face an enemy where mutual assured destruction (MAD) means nothing.

Before anyone gets the woe is me fervor. Recall we have never been able to just freely sail our navy into enemy waters during a big war. England faced Germanys buzz bombs and V1's. Those systems simply keep being refined.
If that doesn't scare you enough to support a strong US military. Then you are a fool.

.30-06 fan
02-22-2015, 01:46 PM
One thing that is obvious. WWII tech will not win any modern wars.

not sure how modern tech deals with gorilla warfare?

GabbyM
02-22-2015, 01:49 PM
Here is the Mk-45 gun system Wiki. I'd forgot they made the mod 4 in 62 caliber length barrel for a 5"x62. Works out to 25.8 feet long barrel.

http://en.wikipedia.org/wiki/5%22/54_caliber_Mark_45_gun#Variants

Recall reading on the Zumwalts they designed in capacity to increase electric generation specifically for rail guns and laser weapons in the future.

GabbyM
02-22-2015, 02:18 PM
not sure how modern tech deals with gorilla warfare?

Well it's perhaps slang. Another name for extended trail or tail chase flight formation. Flight formation in a line. Not necessarily straight line.

I first heard it in talking to Korean war combat vet. Setting up A-26 squadrons to attack miles of road after the Chinese Christmas invasion. They'd fly the squadron "tail chase" "gorilla line" along a mountain road to the IP. Then roll in for a strafe and bomb run on there assigned road section. 21 50 calibers firing forward on pilot command, 1,500 pounds of bombs dropping over and 11 50's firing to the rear upon egress controlled by the turret gunner. Multiply that times two dozen attack aircraft all hitting the same time and you have a long stretch of road with nothing but dead enemy. We kept that up for three days and killed over three hundred thousand Chinese in the mountains there idiot leader ran them into. That after 1.2 million of them could not dislodge sixteen thousand Marines.

factoid: you may not find that exact gun setup on a A-26 listed in an encyclopedia. I was told the squadron was informed by engineers they'd never get them off the ground. But as he said. "We did." They had eight guns in wing pods. Eight hard nose. Turrets and nose stinger had forward lock position and a pilot command switch. Never was clear where all the 11 to the rear were but he said they had them so they did. I think turrets, tail guns and the doors. Would not all fire into same target.

The Chinese of course planned to be through those mountains before the weather cleared for the USAF. But the USMC got plum stubborn about giving up a couple hills. Three day Chinese casualty was almost equal to our entire WWII losses. Whenever I hear people spew about how smart Chinese generals are. I just moan.

Ballistics in Scotland
02-22-2015, 02:26 PM
A 16" shell weighs like a large vehicle.
At 23# this is much smaller.
Once a 23# version is fielded, larger projectile models will be developed.
Radar is used to detect, track, and target airborne targets.
Ground targets are detected by recon aircraft and satellites more often than not. The detection does not have to be recent. Think Google Earth. The real issue is target analysis! Is that an underground hospital or a Command and Control bunker or missile silo? Five year old Google Earth photos could tell.

It has to be real-time detection and communication if the target is moving, and if things like this are going to be around, things that aren't moving at the moment pretty soon will be.

If you make it three times as long as a gun, you can accelerate the projectile to three times the speed with the same acceleration, and therefore stress any internal components no more than with any other unspun projectile. One thing you can't eliminate, though, is recoil, since action equals reaction even if it is only imposed on projectile and rail by electromagnetic force.

Although for legal reasons they are very coy about this, I suspect that weapons in space, even if only in reprisal against an enemy doing the same, have entered into their thinking. The big snag with an ordinary gun, in this situation, is that recoil is liable to throw the firing satellite out of orbit. Various people have planned to eliminate recoil by firing another projectile, even if it was only powdered lead and petroleum jelly, in the opposite direction. But there are so many variables in this that you are unlikely to equalize the recoil, besides the fact that lead powder and petroleum jelly is not something you want in your orbit zone. If you could but achieve escape velocity, however, you could achieve the same acceleration in both directions, and send off the other shell in the direction of aliens who are unlikely to sue in the next few light-years.

Smoke4320
02-22-2015, 02:30 PM
I just want know when NOE will be running a group buy for this mold :) :)

jmort
02-22-2015, 02:35 PM
In the original thread I this, I did the calculations and as I recall, it was around 14 million ft lbs of energy.

Ballistics in Scotland
02-22-2015, 02:38 PM
Well it's perhaps slang. Another name for extended trail or tail chase flight formation. Flight formation in a line. Not necessarily straight line.

I first heard it in talking to Korean war combat vet. Setting up A-26 squadrons to attack miles of road after the Chinese Christmas invasion. They'd fly the squadron "tail chase" "gorilla line" along a mountain road to the IP. Then roll in for a strafe and bomb run on there assigned road section. 21 50 calibers firing forward on pilot command, 1,500 pounds of bombs dropping over and 11 50's firing to the rear upon egress controlled by the turret gunner. Multiply that times two dozen attack aircraft all hitting the same time and you have a long stretch of road with nothing but dead enemy. We kept that up for three days and killed over three hundred thousand Chinese in the mountains there idiot leader ran them into. That after 1.2 million of them could not dislodge sixteen thousand Marines.

factoid: you may not find that exact gun setup on a A-26 listed in an encyclopedia. I was told the squadron was informed by engineers they'd never get them off the ground. But as he said. "We did." They had eight guns in wing pods. Eight hard nose. Turrets and nose stinger had forward lock position and a pilot command switch. Never was clear where all the 11 to the rear were but he said they had them so they did. I think turrets, tail guns and the doors. Would not all fire into same target.

The Chinese of course planned to be through those mountains before the weather cleared for the USAF. But the USMC got plum stubborn about giving up a couple hills. Three day Chinese casualty was almost equal to our entire WWII losses. Whenever I hear people spew about how smart Chinese generals are. I just moan.

Wikipedia has figures of 367,283 to 750,282 Communist dead, including North Koreans, with the higher figure appearing improbable. I suppose other people might have killed a few of them.

GBertolet
02-22-2015, 03:04 PM
Very interesting. The 64K question is, being this is a kinetic weapon, with no warhead or guidance system, what is the probability of a direct hit at say even 75 miles? You will have crosswinds, rotation of the earth, and other unpredictable atmospheric conditions to contend with. An enemy ship will be a mighty small target.

I imagine the navy already knows this, and was giving the 110 mile figure for publicity. It is more likely to be used at more normal ranges.

theperfessor
02-22-2015, 03:12 PM
Well, a .22LR is quoted as having a 1 mile (or sometimes more) dangerous range, but what distance are you shooting squirrels at? I imagine it would be the same here.

MtGun44
02-22-2015, 03:29 PM
I have worked with electronics that would survive many thousands of Gs pulse.
Probably can make them even more capable, but it takes some real careful
analysis and design to make it survive that.

Powder guns do not have anything remotely like constant acceleration on the
projectile. If the rail gun can do that, and it seems reasonable that it can, 7800
ft/sec, if you assume a 1/4 second launch time, is only 968 G constant loading.

Oh, wait; if the "muzzle" speed is 7800, and the rail is 50 ft long, avg speed is
half that or 3900 ft/sec, so rail time will only be 0.0128 second. This
means that the average acceleration needs to be far higher, just over 600,000
(correction, forgot to convert to Gs) feet/sec^2, which is equal to a bit less than 19,000 Gs.

Electronics would likely be able to survive that, but I wonder if a 50 ft rail is practical.

1/4 sec was not a reasonable guess. Since avg rail speed is 3900 fps, a 1/4
sec rail time works out to 975 ft long rail, which is about 100 ft less the full length of an
aircraft carrier, so not feasible, no way to point it accurately. Rails will likely
be 20-30 ft long, something like naval rifle barrels, so a reasonable sized mechanism
can point them.

A 25 ft long rail with a muzzle velocity of 7800 fps, means a rail time of 0.0064 (6.4
milliseconds!!) which will require an average acceleration of 1.2 million (correction:
didn't convert the units here, either) ft/sec^2 which is equal to 37,849 Gs.
May be possible to get electronics to survive this, with careful design and testing.

These will most likely be solid, unguided projectiles, but with some finesse, guidance
may be possible.

NavyVet1959 - thanks for the correction - fixed mine.

NavyVet1959
02-22-2015, 05:43 PM
A 25 ft long rail with a muzzle velocity of 7800 fps, means a rail time of 0.0064 (6.4
milliseconds!!) which will require an average acceleration of 1.2 million Gs. Yikes!


For those curious on the formula for calculating acceleration, it is:

acceleration = (final velocity - initial velocity) / time

Assuming a 50 ft "barrel" and constant acceleration,

average velocity = (final velocity - initial velocity) / 2
= (7800 - 0) / 2 = 3900 fps

time = barrel length / average velocity
= 50 ft / 3900 ft/sec
= 1/78 sec = 0.01282 sec

Thus,

acceleration = (7800 - 0) / (1/78) = 7800 * 78 ft/s2 = 608400 ft/s2

acceleration due to gravity (G) = (approx) 32.174 ft/s2

So,

acceleration in Gs = acceleration in ft/s2 / acceleration due to gravity
= 608,400 / 32.174 = 18,909.68 Gs

Artful
02-22-2015, 07:30 PM
It appears this prototype at Mach 7 is well on it's way of the design of Mach 10 - Mach 12

I think (without doing the math) that at Mach 12 it could send a projectile up to orbital heights.

JSnover
02-22-2015, 08:12 PM
Well, a .22LR is quoted as having a 1 mile (or sometimes more) dangerous range, but what distance are you shooting squirrels at? I imagine it would be the same here.
Right.
The difference between maximum range and maximum effective range.

NavyVet1959
02-22-2015, 08:32 PM
It appears this prototype at Mach 7 is well on it's way of the design of Mach 10 - Mach 12

I think (without doing the math) that at Mach 12 it could send a projectile up to orbital heights.

Orbital *heights* doesn't give you anything unless you have the velocity to continue in the orbit.

Assuming 761.21 mph = Mach 12, then that would be 9,134.52 mph = 13,397.296 ft/sec = 160,767.552 in/sec = 4,083.5 m/sec = 4.08 km/sec. A satellite at an altitude of 200 km needs a velocity of 7.8 km/sec to stay in orbit.

https://www.amacad.org/publications/Section_4.pdf

With the Mercury "Friendship 7" orbital mission, they used 161 km as the orbital height and 28,234 km/hr (7.843 km/sec) as the orbital velocity.

http://en.wikipedia.org/wiki/Project_Mercury

Now, if anyone was wondering the theoretical height that a projectile might rise given an initial velocity and fired straight up:

height = velocity2 / (2 * acceleration due to gravity)

Thus, a Mach 12 projectile could theoretically go as high as:

height = (12 * 761.21)2 / (2 * 32.174) = 1,296,690.7 ft = 245.6 miles.

But that would be just straight up and then it would be coming straight down (possibly right at you).. :)

pertnear
02-22-2015, 08:36 PM
I just want know when NOE will be running a group buy for this mold :) :)
Rumor has it that Lee is working on a two-cavity mold but the old handles won't work. So don't forget to include handles in the group order.

MtGun44
02-22-2015, 11:36 PM
The kinetic energy of one of these projectiles at short ranges will be very high, so
no explosive will be needed, just like current anti-tank ammo.

MtGun44
02-22-2015, 11:39 PM
The kinetic energy of one of these projectiles at short ranges will be very high, so
no explosive will be needed, just like current anti-tank ammo from the M1A1 Abrahms.
At these velocities, aerodynamic heating is very high, and so is drag. I wonder what
the velocity of a 7800 fps projectile will be at a range of 10 miles?

NavyVet1959
02-22-2015, 11:52 PM
TI wonder what
the velocity of a 7800 fps projectile will be at a range of 10 miles?

Maybe someone with Quickload can plug in the numbers? :)

MaryB
02-23-2015, 12:23 AM
And for those who like to experiment at home


http://youtu.be/TWeJsaCiGQ0

MtGun44
02-23-2015, 04:13 AM
Can't help but notice that most projectiles hit sideways (no spin stabilization, probably way
too much friction if they were a tight fit) and that they barely made it through a
pop can. Neat project.

Mark 1, proves the concept, going to need that Mr. Fusion from Back to the Future to power
a serious one.

koehlerrk
02-23-2015, 07:40 AM
The buildings in the background of the vid are part of the US Navy Weapons Lab in Dahlgren VA. I've seen that info mentioned other places/times on this project.

The big reasons for developing the railgun is cost per shot and shipboard safety. $25,000 per shot sounds like a lot to us, but how many $25,000 darts can you fire vs. a single multi-million dollar Tomahawk missile? With no propellant or explosive warhead... the darts are about as dangerous as so many steel bars. That is a HUGE concern on a naval vessel.

As for making them guided... I'm sure they will down the road, in fact, they're probably working on it right now. But the biggest obstacle I see isn't the g-forces on launch, it's the electro-magnetic load seen inside that barrel! You have an electric charge capable of accelerating a 23lb projectile from rest to 7800 fps... you're gonna need one heckuva faraday cage around any onboard electronics or they're going to get slagged.

MtGun44
02-23-2015, 11:00 AM
Just the steel shell should be plenty of a magnetic shield, but I would sure want
to run the tests on simple circuits before doing any expensive stuff. Faraday cage effect
is for electric fields and currents like a lightning strike rather than magnetic fields.

Artful
02-23-2015, 02:12 PM
Orbital *heights* doesn't give you anything unless you have the velocity to continue in the orbit.

Assuming 761.21 mph = Mach 12, then that would be 9,134.52 mph = 13,397.296 ft/sec = 160,767.552 in/sec = 4,083.5 m/sec = 4.08 km/sec. A satellite at an altitude of 200 km needs a velocity of 7.8 km/sec to stay in orbit.

With the Mercury "Friendship 7" orbital mission, they used 161 km as the orbital height and 28,234 km/hr (7.843 km/sec) as the orbital velocity.

Now, if anyone was wondering the theoretical height that a projectile might rise given an initial velocity and fired straight up:

height = velocity2 / (2 * acceleration due to gravity)

Thus, a Mach 12 projectile could theoretically go as high as:

height = (12 * 761.21)2 / (2 * 32.174) = 1,296,690.7 ft = 245.6 miles.

But that would be just straight up and then it would be coming straight down (possibly right at you).. :)

The trick of course is to shoot a moving satellite from your moving ship with a 23 lb object intersecting at 7.8 km/sec you again don't need an explosive charge to take out the eyes and ears of your enemy - and shooting a laser at a metal dart may vaporize some of it but enough should be left to stop the service life of an orbital platform.

NavyVet1959
02-23-2015, 04:45 PM
The trick of course is to shoot a moving satellite from your moving ship with a 23 lb object intersecting at 7.8 km/sec you again don't need an explosive charge to take out the eyes and ears of your enemy - and shooting a laser at a metal dart may vaporize some of it but enough should be left to stop the service life of an orbital platform.

I don't think we want to get into the habit of shooting satellites. There's enough space junk up there already without us adding to it my letting a satellite hit our projectile at 7.8 km/sec. All you need to do is get the projectile up to the orbit of the satellite and let the satellite hit it. Even better would be to have a projectile that could separate into a bunch of pieces so that it would be more of a "shotgun blast" chance of hitting it.

lefty o
02-23-2015, 05:00 PM
not to worried about using one of these rail gun projectiles for anti sattelite work, we've already proven a ticonderoga cruiser can smoke a sattelite. these solid projectiles may be ok for putting holes in a hardened target, but imo would likely pass through the superstructure of a ship doing minimal damage. for the time being , id still rather have a shell with some explosives in it.

w5pv
02-23-2015, 05:04 PM
I think I have read where the Navy has a prototype mounted on a ship doing test now.

TXGunNut
02-23-2015, 11:03 PM
I guess those bags of WWII black powder are pretty much gone, still hard to wrap my head around the sheer numbers of this rail gun.

Three44s
02-24-2015, 01:08 AM
How about an orbiting rail gun?

Three 44s

MtGun44
02-24-2015, 01:11 PM
No black powder used in WW2 AFAIK except inside hand grenades. Certainly not for
propellant in naval rifles, that was normal smokeless powder with grains as big
as your thumb in the 16 guns, seven holes down the length of each grain.

An orbiting rail gun will suffer from the recoil moving it around in it's orbit. Either
need to launch a 'recoil projectile' the opposite direction or fire a rocket motor.

And the problem that if anyone blows up any satellite, the pieces become semi-permanent
hazards to navigation for everyone else.

Artful
02-24-2015, 08:27 PM
https://www.youtube.com/watch?v=7aBO_ZRgqNw

Artful
02-24-2015, 08:30 PM
https://www.youtube.com/watch?v=L915JJMcu4s

Got-R-Did
02-24-2015, 10:26 PM
132030132031
Propellant like this? .50 BMG AP projectile for scale.
Got-R-Did.

MaryB
02-24-2015, 11:50 PM
I applied to have my telescope used when I am not out there to track orbital debris. Program got cut before they got most of it set up so only about 20 tracking stations. I would have gotten a free scope upgrade out of the deal. Soon as someone figures out how to get up there cheap they could recover a heck of a lot of gold by capturing dead satellites and bringing them back for recycling.



https://www.youtube.com/watch?v=L915JJMcu4s

BAGTIC
02-25-2015, 12:01 AM
The high velocity fin stabilized projectiles have far less drag than do spin stabilied projectiles.

BAGTIC
02-25-2015, 12:03 AM
Don't need a high velocity launcher to launch from space. Gravity will provide more than enough velocity.

BAGTIC
02-25-2015, 12:08 AM
Much of the range will be at high altitude where drag and heating will be much lower.

BAGTIC
02-25-2015, 12:20 AM
The giant muzzleloader wouldn't have a chance against a modern 5 inch gun. The ML would be outranged and its fire control system would not be able to score a hit against a maneuvering target.

Ballistics in Scotland
02-25-2015, 09:17 AM
Well, a .22LR is quoted as having a 1 mile (or sometimes more) dangerous range, but what distance are you shooting squirrels at? I imagine it would be the same here.

This probably depends on numerous atmospheric variables, but I think 1200 or 1300 yards is a more reliable figure. The thing is, he consumer only has a right for his purchase to fulfill its intended purpose. He can't sue because the cartridge didn't reach someone a mile off, or bounced off his forehead. He can only sue if it did at longer range than he was warned of.

Ballistics in Scotland
02-25-2015, 09:24 AM
The giant muzzleloader wouldn't have a chance against a modern 5 inch gun. The ML would be outranged and its fire control system would not be able to score a hit against a maneuvering target.

I knew there must be some reason why they don't use them any more. Others too, I don't doubt. But its power was immense against anything but heavy armour, and its intrinsic accuracy was pretty good. I saw a trial on History Channel in which a Civil War Parrot rifle convincingly thrashed the Canadian army's modern field-gun at 1000 yards, for pure accuracy. Again, that wasn't an adequate test of effectiveness. The modern gun would have a very different sort of shrapnel, if they fired shrapnel, or penetrator if they were armour-piercing. But good black powder is a very consistently burning propellent.

Alan in Vermont
02-25-2015, 07:48 PM
Navy quoted (about 5300 mph or 7800 fps)

Slight correction, 5300 mph comes out to 19,080,000 fps. Pretty impressive.

You better go do the math again, 7800 fps is pretty darn close