The XM25 autocannon is neat. Absolutely nobody denies this. It's also pretty useless, because any insurgent who engages security forces in a conventional gun battle is going to die. Nine times out of ten, they're dead; if by airstrike or just being outflanked and outgunned.
They know this, which is why for the last nine years, the weapon of choice used by the other side has been the IED or the suicide bomb; where high tech weapons like the XM25 are rendered entirely useless. While it's nice to see the Economist running an advertisement for Alliant Techsystems in their magazine, the XM25 will actually do very little to win CI wars.
There's a real use for this weapon. If it works, it's not a pointless economic stimulus tech demo. US troops get into plenty of firefights with insurgents. Artillery and air support must be around if we plan to win those firefights with low casualties. The XM25 makes artillery and air support less of a necessity, which means we could save money and gas.
Saving gas is important. If you're shipping gas or ammo by truck, you're creating targets for IEDs. Our casualty rates would be significantly higher if we couldn't use foreign drivers. The DARPA self driving car challenge was a response to the IED turkey shoot that's our supply line. At least we can avoid casualties.
yes its just a replacement for the existing under barrel launchers M203 and the venerable Vietnam era M79 this gives that gives you a few more tactical options.
"A few more tactical options" is playing down something that can be monumental.
The howitzer only offered "a few more tactical options", mainly being the ability to lay down accurate indirect fire whilst still being able to offer direct fire and defensive fire.
I mean why bother inventing gunpowder or rifling or any other weapons when an arrow killed people too. I mean sure the rifle was more effective and less competent soldiers could use it skilfully, but what was the point when we already had bows and crossbows?
So why bother inventing an accurate method of firing a frag round at 500ft when the M203 has a max range of 400ft and effective fire at only 150ft. Granted the AK47 is only effective at 250ft, but that still means the soldiers will be spraying and praying with grenade fire.
The whole point of making a weapon more accurate and effective is to increase the enemy combatant losses whilst decreasing civilian losses and soldier risk.
The American battle rifles aren't a weakness, they serve their purpose well. The military should be focused on things like IED detection, preventing brain damage from concussive force, battlefield intelligence, social programs (hearts and minds)... the stuff we are having a hard time doing.
The M4 is accurate, but lacks the power of something like an AK-47, which hits harder and has a larger round. It's great for clearing a room or working in tight spaces, but it's not nearly the same as this.
Additionally, they are working VERY hard to improve IED detection, and in fact are making quite a bit of headway in that regard. The same goes for every other issue you raised.
There's no reason you can't improve offense while simultaneously improving defense.
Improving offence helps you improve defence. If you make the most dangerous weapons in the world, then you solely have the ability to figure out the best ways to defend against them.
The US will have a significant advantage in developing jamming systems against these types of rounds.
The US isn't afraid of some Afghan insurgent living in a cave from developing a countermeasure against these new munitions. They're afraid Russia or China will be capable of developing a countermeasure. The rounds are worthless, or potentially dangerous, if you can cause premature detonation.
Brecher (not "Breacher") doesn't know any more about war or geopolitics than you or I.
The fact that this particular weapon isn't useful in an IED attack doesn't mean that it's not useful for what it's designed to do. You seem to be under the impression there's no shooting going on in A-stan. This is definitely not the case.
The accuracy of a rifle with a frag round have a lot of potential. I mean, if you're taking fire from a window you range find to the wall the window is on, add a foot and fire it through, the round will explode a foot or two from the combatant. Know there's four enemy in a vehicle, range find and aim for a side window.
It will certainly change the way soldiers will fight, but the advantage is that the insurgents and less developed nations won't have the technology and likely won't have the understanding of it. Everyone knows grenade launchers lob the round. However, it's going to be very different when it's got the range and the level trajectory of a rifle.
My stab at how the bullet measures its own rotation:
Suppose the bullet leaves the muzzle rotating at 300,000 RPM (quite reasonable for a rifle). That is 5kHz. It's easily within the capabilities of a Hall Effect sensor to measure a 5kHz rotation and so I'd make the very centre of the bullet contain a free rotating magnet. The rifle itself sets the magnet spinning at some known rate opposite to the rifling. When the bullet leaves the rifle it is able to measure the time between detections of the magnet and given the known rifling, the known magnet rotation speed it would be able to calculate rotations.
Alternatively, the inner magnet could be spinning in the same direction as the rifling but faster and detect complete rotations of the bullet. Either way I think Hall Effect + spinning magnet at bullet core would work.
Also, 5kHz is well within the operating range of a micro controller so this wouldn't need much computer power. Lastly the article says that the weapon is accurate at 500m and that the shrapnel kills everyone within a few meters. Also says that the soldier estimates the target distance.
That sounds like there's plenty of room for the measurement to be not too accurate. Suppose 'several meters' is 5 then you can get away with an error of 1% or so.
I suspect it would be easier to make the front spin and fin-stabilise the rear than try to make a rotating core. That being said, given a known muzzle velocity I don't understand why it's not a simple timing problem.
Still easier to have temperature and pressure sensors at the weapon( they fit in a wrist watch so there should be no problem to do the same at a high tech gun) and send a rectified time input to the bullet IMHO.
Ten years ago, I had a $2 top with LED lights which cleverly displayed words in a fixed position by using a sensor to use the earth's magnetic field as a reference.
For 500 meters against the wind it would not guarantee a stable velocity, thus not a stable path length over certain time (it would probably be non-linear to calculate).
So, it seems to exist a correlation between the RPM of the projectile and its velocity over wind's influence that guarantee a linear calculation over the RPM of the projectile.
>Also says that the soldier estimates the target distance.
If the target is behind a rock, the soldier uses a laser rangefinder built into the gun to get the distance to the rock, and then inputs into the gun "the target is 2m behind the front of the rock". So, unless the explosion radius is small, the soldier has to make sure the bullet explodes behind whatever is between the rifle and the target.
Given that this is basically an ultra-fast artillery device, the tech in this gun more likely represents a natural evolution of applied external ballistics (http://en.wikipedia.org/wiki/External_ballistics) - incidentally this is a purpose for which the ENIAC was designed. I bet the magic has more to do with being able to collect and characterize environmental data through sensors and plug these meaningfully into Ballistic models.
They could just put a coil in the bullet and a permanent magnet along the barrel, then measure frequency produced by the temporary dynamo to calculate velocity (based on known rifling). Then use a timer to measure distance.
That's a plausible explanation!
It may also be a small accelerometer able to calculate the rotation. The free rotating theory seems very correct though.
I'd go with magnet but, I think it ma all be solid state so, accelerometer came to mind.
The article says that the grenade's travel distance is measured by counting its rotations, implying that the barrel is, in fact, rifled. (Maybe that doesn't technically make it a rifle, but it doesn't seem like a terribly inaccurate term.)
Technically true; however, in practice, you must rifle the barrel of any grenade launcher, or else have tail fins on the grenades to prevent aerodynamic tumbling. Tank guns, cannons, howitzers, and the like typically have rifled barrels but we don't call them rifles. (Mortars, on the other hand, use finned ordnance.) AFAIK rifles are usually defined to have a caliber at most 20mm.
The British have been trying to replace that rifled gun with the German L/55 smoothbore, too, but they don't have the money. It wasn't clear at the time the tank was designed, but the rifled barrel turns out to have been a mistake. The round for which it was primarily designed (High Explosive Squash Head, or HESH) hit a sort of technical dead end with the introduction of spall liners and layered composites in tank armor.
Read the comment by Steven Den Beste, who explains the situation pretty well (aside from getting the HESH acronym wrong):
True, it is grenade launcher. One thing that makes it more rifle like is the trajectory, it's much flatter than a 40mm grenade launcher. M203 and M320 grenade launchers launch long range grenades in a high arch, like a long football pass.
$25 bullets and $25000 rifles are insanely expensive. And I don't see how better rifles will bring an advantage - most coalition casualties are from mortar fire and improvised explosive traps - rebels have already lost preference for gun standoffs. But I'm sure H&K and Alliant will love to sell lots of these to whatever army is corrupt enough to buy them.
Also... aren't exploding bullets illegal under the Hague convention?
The Hague forbids bullets that expand on penetration, on the basis that it creates larger and more traumatic wounds. This round acts more like a grenade. It explodes (and wounds/kill by shrapnel) near the target. It shouldn't actually hit the person. Completely different class of weapon. It's more accurate to call this a grenade launcher than a rifle.
It always seems so absurd to me that there are rules around wartime killing. Once you acknowledge that it is acceptable to take another person's life for profit you really have little credibility for laying out rules of fairness.
Well, most of the rules aren't about killing per se, but rather wounding. And most of the rules are in place so that the stakes of fighting never gets high enough that we would all have to stop fighting. For example, the Geneva Protocol that bans chemical and biological weapons pretty much because aside from killing, those who were wounded were an enormous burden, and terrible for morale (aside from any ethical reasons).
In that case, losing the ability to use those weapons was deemed to be outweighed by the consequences of having to deal with them being used on you. Also, since they could be potentially huge and unpredictable force multipliers, it made war all the more predictable, which is good from their perspective.
Long story short, nearly all rules of war exist because they are beneficial to abilities of the parties to conduct war. The rules do no exist to make killing fair. They exist so that parties may conduct war in a way they agree with.
"Long story short, nearly all rules of war exist because they are beneficial to abilities of the parties to conduct war. The rules do no exist to make killing fair."
That actually makes perfect sense. Although I find it rather disturbing.
War without rules would be a greater horror. Even the ancients had them (Julius Caesar himself was charged with war crimes). How could closure and peace be negotiated, for example, without protection for emissaries.
You were on your way to an interesting point until you made the implicit claim that war is always about profit. For pretty much every war, that isn't true for at least one side, and often for both.
Obviously one side isn't necessarily in it for profit, they could simply be defending the other side's actions. But the instigator is usually in it for profit.
IANAL but that has some problems. First of all the convention mandates 'declaration of war' in a sense that you have to tell someone you're attacking. If it was skipped then it was against the part of the convention mandating such notification.
Secondly the other parts of the convention do not talk about war as a set of specific circumstances (e.g requiring declaration of war) but just hostilities regardless on how they originated.
So by skipping the declaration of war one simply breaks one additional part of the convention, the one mandating the declaration.
It's a 25mm explosive round, not a rifle round, so $25 isn't out of the question. I don't know how much an M203 grenade costs in bulk, but that would be a suitable comparison.
It's really a misnomer to call this thing a rifle. Yes, it has a rifled barrel. But it's a grenade launcher, not a rifle in common parlance. It replaces the 40mm grenade launcher in use.
In this era of global mass instantaneous communications, every citizen of every country is our neighbor. There is no excuse for the continued existence of this disgusting military industrial complex.
The only things keeping this going are racism, ignorance or misperception fueled by propaganda, and a sick, inhuman and outdated Social Darwinism.
We just cannot permit criminals and thugs to continue to have control.
Surely it's just a 1 axis accelerometer and perhaps a lookup table or some basic maths?
The military sure do like to make themselves seem important. Super secret alien assault rifles being attacked by unspecified hackers from unknown locations. Yep, better keep funding new and exciting ways to kill people.
Hmm, would the accelerometer really detect anything? I think the bullet would have to experience significant lift, otherwise it's in free fall and the only acceleration you'll see after it leaves the barrel is air resistance, which isn't in the right direction to change with each rotation. To a first approximation, spinning bullets don't experience lift.
Maybe there's still some minuscule effect that can be detected, though. The sections on Magnus force in http://www.nennstiel-ruprecht.de/bullfly/index.htm seem to suggest that this is the case. But now I'm not so sure it's as simple as counting the number of periods of oscillation from the accelerometer.
IANAIBOEP (I am not an expert in ballistics or even physics)
I was thinking of the accelerometer being located near the outside of the shell, rather than relatively stationary near the centre of rotation. I agree it's not entirely trivial, but it seems pretty doable to me.
The accelerometer cannot measure the earths gravity which was probably what the GP suggested. However you can measure the centrifugal force (http://xkcd.com/123/) which may be more precise than trying to measure the muzzle velocity or just assuming certain known muzzle velocity.
No. An accelerometer measures change in acceleration.
When the round is fired, it will experience a huge acceleration from the propellant along its axis plus a very large rotational acceleration as the rifling spins the round from 0 revolutions per second to a large number of revolutions per second.
Once the round leaves the barrel, it is falling at a constant acceleration (9.8m/s, freefall, 0G, "weightlessness"), so it will not be able to measure the earth's gravitational force. It also will be spinning at a constant rate because there is no outside force increasing or decreasing the spin rate, thus no rotational acceleration. While there will be acceleration due to the centripetal effect of the rotation, that acceleration is constant and thus not usable with an accelerometer for counting revolutions.
I got it wrong in my first sentence - in order for an accelerometer to be used, there has to be changes in acceleration proportional to distance travelled. Per the rest of the discussion, there isn't any.
You still have it wrong. An accelerometer measures acceleration.
Users usually calibrate the device at rest to get a good estimate of G so that it can be subtracted from accelerations measured later. Is that what you mean?
No. A falling object is at "0G", it is "weightless" (in a "drop seat" type carnival ride, when the ride triggers, you have no force on your butt). A bullet is a falling object after it leaves the gun. You cannot measure earth's gravitational attraction from the bullet's frame of reference because it is 0. Therefore, you cannot use earth's gravitational attraction to measure the bullet's spin rate because the value is zero, and zero has no direction information.
Sure, once the bullet is moving ballistically you can't measure G. My argument was with the statement that accelerometers measure changes in acceleration. They don't.
All the positive acceleration happens in a very short time. It might be hard to measure it frequently and accurately enough to use the integrated results as a velocity estimate.
Perhaps measuring the negative acceleration caused by air friction could give you a velocity estimate (the velocity-to-friction function is probably non-linear). But this may vary a bit with air density, temperature, etc.
I'd be interested to see how it's done. My bet is that it's not directly measuring a near-impulse acceleration.
Something along the lines of RFID? I've heard them described as "radio controlled" before too.
Since it's in the chamber protecting it from external sources of interference / attack (e.g. programmed to explode at the end of the muzzle) should be easy to protect against physically. I guess you could do it with some mechanically retractable pins or something, but electrical contacts and the inside of a bullet chamber don't seem like the sort of thing that should go together to me. You'd need to clean them constantly.
Presumably they got their security right; no recommit after firing, for instance.
If not, I can easily imagine a "bullet jammer" gizmo that broadcasts a retargeting command. "Sorry, little grenade, you have another thousand meters to go...."
I guess our economy will never completely bottom out as long as we can export death.
Just wait 'til your local police get these for "domestic terrorism crowd control" (aka protesters) with the shrapnel replaced by "less lethal" rubber bullets while drones fly overhead for more accurate targeting.
Oh it would never happen, right? What if a congressman owns stock in the company?
Yep. It'll be great for this company once the regulations are loosened and they can begin selling to all the countries onnafrica, the middle east, western Europe, and Asia. Bad for everyone else though.
Sounds like a good way to counter this sort of weapon would be to have human shields. I'm not sure if that's an improvement on the situation if they start to adopt those sort of tactics.
Enemies will simply adapt to new weapons they face. Much like a bucket of paint would be quite effective against and remote control mini tank.
Whilst the engineering feat is impressive, it is still important to note that at the receiving end of such ingenuity is a writhing half dead corpse so it is with hesitation I would ever celebrate such innovation.
It's a grenade launcher, not a rifle. (you can have rifled barrels in a grenade launcher, doesn't make it a rifle) and a TOT detonation's hardly the most amazing thing ever. It's just another example of mobile infantry artillery, it's expensive and it's just another horrible way to die.
The morality is in deciding when it is worth ending a human life. What tool you use is a distant second, at best. In war, once you have decided to kill a person, the moral course is to kill them as quickly and effectively as possible. Preferably with as little pain as possible.
The tools are horrible, because war is horrible. If you're opposed to their use, you need to act at the political level (to stop unnecessary war from happening) or the strategic level (to win the conflict in a way that does not require direct, physical confrontation)
Regardless of the tactical implications of this particular weapon... the fact they're now making computerized bullets makes me wonder where else this path will lead.
The XM25 autocannon is neat. Absolutely nobody denies this. It's also pretty useless, because any insurgent who engages security forces in a conventional gun battle is going to die. Nine times out of ten, they're dead; if by airstrike or just being outflanked and outgunned.
They know this, which is why for the last nine years, the weapon of choice used by the other side has been the IED or the suicide bomb; where high tech weapons like the XM25 are rendered entirely useless. While it's nice to see the Economist running an advertisement for Alliant Techsystems in their magazine, the XM25 will actually do very little to win CI wars.