Heavy Tri-barrels

Just a side note: 5.56mm and 22LR are roughly equivalent, as far as caliber. Obviously not the same as far as range, muzzle velocity, stopping power, and accuracy.

Now, before anyone jumps down my throat about this, note the "roughly" up there.

When I went through weapons training at Lackland AFB, we were trained on M-16's using adapters (for the magazines) to fire 22LR rounds through an otherwise stock weapon. For Air Force training for folks who weren't actually going to be *using* the damn things in their daily jobs, it's close enough for gub'mint work.

Once I was stationed in England, I received more training, this time with actual 5.56 ammo. Only went to the range once, though - it was more for familiarization, rather than serious training.

Several people here have mentioned recoil, and advanced recoil suppression, etc.

I thought I would just remind everyone that for the HV heavy tri-barrel, we are talking about a tri-barrel pulser, basically using rail gun type physics, not chemical propellant physics.

Someone remarked that the recoil would be 'less of a problem'. Actually, if I understand David's explanations of pulsers, the recoil of this weapon would be virtually nil, with any firing instability deriving mainly from the weight of the round being removed from the system upon firing (a really tiny difference, round to round), from the resistance of the air to the round itself, and possibly from air attempting to return to the vacuum created in and ahead of the barrel by the passage of the hypervelocity rounds.

There is no large Newtonian reactive push from a burst of energy behind the projectile. The dart is accelerated down the barrel, probably not actually in contact with the barrel once firing is initiated, by a tiny gravitic 'ripple' traveling along the elements of the barrel. If everything is in balance, I would expect only minutely more 'recoil' than from a beam weapon.

dreamrider

(PS - Expecting RFC to weigh in on this thread any day now.)

But rail guns still have recoil. Conservation of momentum still applies.
Mass (bullet) x Velocity (bullet) = Mass (weapon system) x Velocity (weapon system)

The weapon system is much heavier, so it it is moving a lot slower, but it will move or something needs to absorb that energy.

For lots of detail on how to calculate things like the actual recoil force see http://www.saami.org/PubResources/GunRecoilFormulae.pdf

Too lazy to either do the research myself to find it or the maths, but on a previous thread that I started Namelessfly did the maths that showed a standard 4.5mm pulsar round had about the same kinetic energy as a 50 cal round. I don't think you could readily fire a 50 cal from a small handgun due to recoil, so the technology must limit recoil.

That may well be the case, but it isn't going to be an inherent effect of not using an explosive to accelerate the round.

kzt wrote:But rail guns still have recoil. Conservation of momentum still applies.

Pulsers aren't exactly rail guns.

Whether recoil negation is designed into Pulsers or an inherent feature of grav drivers, the fact remains that Honorverse Tech minimizes recoil in a way that would drive Sir Isaac crazy.

dreamrider wrote:I thought I would just remind everyone that for the HV heavy tri-barrel, we are talking about a tri-barrel pulser, basically using rail gun type physics, not chemical propellant physics.

And railguns have EXACTLY as much recoil as chemically powered guns if the forces involved are the same.

Please keep in mind that to the current military planners and designers of this world, "man portable" means a weapon breaks down into loads of 25 to 60 pounds for a crew of 2 to 5 operators and assistants.

Most machine guns ever made were in some version "man-portable", including the M2 .50 (although, having humped a portion of that load, I'd say that one is pushing it.)

"Man-portable" does NOT mean carried and operated by 1 man. At the least, it usually means 1 guy carries the unitary weapon as his extra load, and 1 helper carries the basic load of ammo as his extra. Some so-called "man-portable" weapons (the 81mm mortar comes to mind) might need a crew of 5-6 to hump all their components and a useful bit of ammo.

Quite true, sorry i should have been more specific on what i was talking about, as heavy tri-barrels have been specifically stated to be used by single persons, i guess man-operable is the correct definition?

I say again,
"Remember to adjust for 2000 years of development...", etc.

Sure, but do recall that physics still apply. You may be able to cheat physics more or less, but you can´t remove it.

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Pulsers aren't exactly rail guns.

Whether recoil negation is designed into Pulsers or an inherent feature of grav drivers, the fact remains that Honorverse Tech minimizes recoil in a way that would drive Sir Isaac crazy.

I´m not so sure about that, I recall textevs suggesting the recoil is still there. Or at least some of it.

I real world terms, the XM214 cited by kzt is probably pushing the limits of man portable, but the real world doesn't have San Martinos, Ndebelese, sphinxians, or other heavy worlders in powered battle armor to compensate for recoil and weight.

Seriously, you do not wish to try and have a XM214 used by a single person off-mount.
It´s potentially backbreaking in the literal sense.

Just as a wag, the Honorverse should be able to support five or ten times the weight and recoil -- 27.8mm to 55.6mm through handwavium anti-recoil tech and unobtainium weight reduction.

No, just no.


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I don't think you could readily fire a 50 cal from a small handgun due to recoil, so the technology must limit recoil.

You can, but not nicely so and not on auto.

Tenshinai wrote:

dreamrider wrote:I don't think you could readily fire a 50 cal from a small handgun due to recoil, so the technology must limit recoil.

You can, but not nicely so and not on auto.

I think that would be the .50 caliber pistol round, not the .50 caliber machine gun / rifle round.
[Edit] For a rough idea of the size comparison, consider the fact that a US Dollar bill will almost entirely cover my hand. And I have what I think are average size hands for a man. Since the pistol's grip is held by your hand, consider that the height of the machine gun / rifle round alone is taller than the pistol grip of the .50 caliber pistol. And the ammunition for the pistol is stacked laying horizontally in the ammunition magazine, which fits into the magazine well of the pistol grip. [End Edit]

I don't even want to think what the recoil would be even from firing one round [Edit] even two-handed while standing [End Edit] if someone somehow managed to design and build a pistol that was able to fire the machine gun / rifle round.

This animation shows the difference in size of various ammunition calibers. The largest pistol round shown is .50 caliber. The .50 caliber machine gun / rifle round is the third largest shown in the second group.

Edited to correct punctuation and to add comparison points.

Tenshinai wrote:

dreamrider wrote:...And then again...

The following is from a GD video posted to YouTube,

http://www.youtube.com/watch?v=X1VMHQzwDwc

(Remember to adjust for 2000 years of development, portable power supplies that can power contra-grave units and armored suits, tri-barreled not 5-6 barreled, caseless ammo, nano-optimized exotic materials, San Martinos & Sphinxians, and powered armor.)

(Also recall that 'heavy' tri-barrels in the HV are portable arms, not personal arms, unless the user IS in powered armor.)

You realise that that can only manage at best about 1/3 of the rate of fire of the HV tri-barrel.

And can only do so from a vehicle that weighs SEVERAL tons.

Look at how the hummer moves from the recoil when firing sideways. That´s the 5ton version if i´m seeing right.

The PR folks says it has an "average" recoil force of 2.2kN. That´s 220kg worth of push. Or about a quarter of the power in the first generation engines of WWII jet fighters(i checked and it´s actually exactly 1/4 of the power of the Me-262 engines)...

You can also take notice that when they fire from the helicopter, there´s noticeable shaking, and the pilot has to turn against the recoil to compensate(notice what happens when it stops firing, it takes a moment for the pilot to stop compensating).

(that kind of gun should REALLY be in a spinal mount on a helicopter, sheesh!)



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Skimpy, can you post a link the 14mm/14.5mm gatling you cited, please? Google can't find it.

Ugh, it´s a rotary, not a Gatling. A Gatling weapon is a specific subset of rotaries. It´s like calling an M-16 an AK-47 because both are automatic weapons.

I'm glad someone else is as bad at Math as I am.

The idea that 2.5KG per Second is going to throw someone in battle armour is laughable. That is about the same as a 3/4 inch garden hose at 50 psi over 50 feet. As if that could throw anyone around let alone someone in battle armour.

Recoil could cause more of a problem but that is tied to the force motivating the round out of the gun not so much the weight/mass being expelled.

I'll have to look up the link. The problem finding a link to something that wasn't on the official books and before the internet was widely available makes it hard to find stuff.

Lord Skimper wrote:

Tenshinai wrote:You realise that that can only manage at best about 1/3 of the rate of fire of the HV tri-barrel.

And can only do so from a vehicle that weighs SEVERAL tons.

Look at how the hummer moves from the recoil when firing sideways. That´s the 5ton version if i´m seeing right.

The PR folks says it has an "average" recoil force of 2.2kN. That´s 220kg worth of push. Or about a quarter of the power in the first generation engines of WWII jet fighters(i checked and it´s actually exactly 1/4 of the power of the Me-262 engines)...

You can also take notice that when they fire from the helicopter, there´s noticeable shaking, and the pilot has to turn against the recoil to compensate(notice what happens when it stops firing, it takes a moment for the pilot to stop compensating).

(that kind of gun should REALLY be in a spinal mount on a helicopter, sheesh!)

I'm glad someone else is as bad at Math as I am.

The idea that 2.5KG per Second is going to throw someone in battle armour is laughable. That is about the same as a 3/4 inch garden hose at 50 psi over 50 feet. As if that could throw anyone around let alone someone in battle armour.

I'll have to look up the link.

Skimper you don't get physics, stop trying to argue with people who do. The 2.2kN/220kg force is not per second (notice the lack of seconds in the units), its instantaneous, ie that force is being (on average) continuously applied while the gun is being fired. So if the person in battle armor and gun (and ammo ect) weigh less than 220kg and fire they can literally use it to take off and fly around by firing it downwards.