AP Rounds/Missiles

[jaymz]

I make the Boomgun solid slug...I just can't believe that may "shards" can go 2 miles without losing coherency so to speak.

[Mack]

I endorse using the AP rule (crit on 17+, triple on Nat 20) on railguns and certain rifle-launched grenades. Otherwise there's very little reason to lug the heavy things around instead of a energy weapon.

And I apply it to all railguns, including the GB's Boom Gun. Really makes you think twice about facing one when you consider that with bonuses the GB pilot has a decent chance of hitting for 3D6x20 (average of 210 MD) and a 5% chance of hitting for 3D6x30 (average of 315 MD).

funny thing, the glitter boy is probably the one i would be least inclined to consider armour-piercing, considering it is basically firing grapeshot. very nicely made grapeshot as opposed to improvised grapeshot, granted, but still... grapeshot.

True, but keep in mind that just about every other railgun fires a burst. I tend to think of the GB's Boom Gun as firing a 'burst' all at once instead of over a second or two.

(And I agree with jaymz... just make it a slug.)

[Killer Cyborg]

I've never seen grapes that look like flechettes.

[flatline]

Modern artillery is routinely placed on-target accurately over 26 miles, and that's just a bomb sailing through the air. I'm sure future technology could allow 2 miles for flechettes.

Other thoughts: 2 miles for direct fire seems less than plausible for shoulder-fired weaponry, unless some outstanding optics are being employed.

Even with "perfect" optics, it's still not plausible for unguided man-fired projectiles. At 2 miles, the variation between your first shot using a cold barrel and your second shot using a warm barrel will be enough to move your shot off target.

--flatline

[Killer Cyborg]

Modern artillery is routinely placed on-target accurately over 26 miles, and that's just a bomb sailing through the air. I'm sure future technology could allow 2 miles for flechettes.

Other thoughts: 2 miles for direct fire seems less than plausible for shoulder-fired weaponry, unless some outstanding optics are being employed.

Even with "perfect" optics, it's still not plausible for unguided man-fired projectiles. At 2 miles, the variation between your first shot using a cold barrel and your second shot using a warm barrel will be enough to move your shot off target.

--flatline

For all we know, the Boom Gun barrel is always cold.
Or hot.

Or maybe it's not, but molecularly-bonded super-alloys don't expand and contract as much as modern steel does.

[glitterboy2098]

it's amazing what you can do with computer aided aiming.. the M1 abrams has similar issues with its shots, and it has had a computer able to adjust for all that since the 80's.

a glitterboy's boomgun may look like a handheld weapon, but it is mounted on a suit with motors and forcefeedback systems for movement, and powerful computers. i see no problem believing that it has aiming aids on par with the M1.

as for the projectile issue.. your assuming the sabot falls away immediately upon firing. given there is about 3 inches of unused space in the sabot (4 layers of 1 inch long darts, but the round itself is 7 inches long), something like a programmable timed fuze charge to release the darts at a specific distance from the target is perfectly plausible. this would also explain the targeting sight built directly above the barrel.. range finder so the gun can automatically program it's projectiles to burst at the right distance from the target without firer input.

[flatline]

Sorry, I wasn't talking about the boomgun. I don't consider that to be "man-fired".

Once you get to larger projectiles that are mostly immune to air density changes or wind and more sophisticated targeting and firing systems like what you might find on a modern tank (or in rifts power armor), then being able to put an unguided projectile into a head-sized target is completely plausible...

...but not if such weapons are firing multiple tiny projectiles. The boomgun should be firing a single projectile. The idea of flechettes is just stupid unless you're attacking soft targets which is clearly not the intent of the boomgun.

--flatline

[Alrik Vas]

The boom gun round should burst into flechettes inside it's target, firing them outward instead of forward to maximize internal damage post penetration.

AP/Reactive boom gun rounds seem like the best to me.

[Alrik Vas]

Right, so dependant upon GM whether or not you can do it in place of a parry or dodge.

No tactic will work if the GM decides it won't.

Perhaps I've been fortunate to always have a GM that allows defensive spells to be used in place of a dodge, assuming you can cast them in one action. Heck, with the new casting times from RUE, I'd expect Energy Field to be way more popular now than it used to be.

--flatline

As long as a spell/power/whatever takes one action or less, I let them be used as a parry or dodge if it seems reasonable.

So long as they have to make a roll. I see it as something akin to a dragon's teleport dodge if anything.

Blargh double post.

[Killer Cyborg]

Sorry, I wasn't talking about the boomgun. I don't consider that to be "man-fired".

Cool.

The idea of flechettes is just stupid unless you're attacking soft targets which is clearly not the intent of the boomgun.

That might depend on how sharp the flechettes are.

But I agree that it probably should have been more of a cannon, and less of a shotgun.

[flatline]

The boom gun round should burst into flechettes inside it's target, firing them outward instead of forward to maximize internal damage post penetration.

AP/Reactive boom gun rounds seem like the best to me.

I can totally get behind that idea. In fact, there's no reason why there couldn't be a whole range of boomgun rounds for different purposes: fragmentation with proximity fuse for anti-aircraft (assuming they're fast enough you can't hit them directly), solid slug for cheap target practice, sabot rounds with solid penetrator centers (or whatever), incendiary rounds, robot drone rounds, etc.

None of those are possible if the round is expected to break apart whilst inside the boomgun.

--flatline

[Shark_Force]

True, but keep in mind that just about every other railgun fires a burst. I tend to think of the GB's Boom Gun as firing a 'burst' all at once instead of over a second or two.

(And I agree with jaymz... just make it a slug.)

redone as a slug (and in fact, the same for the vast majority of railguns) would be fine with me.

and most railgun ammo isn't really described... but at least i can presume a railgun is using ammunition(smaller than would be found in a slug-throwing boom gun obviously) designed for penetrating armour. flechettes are not used for penetrating armour.

[jaymz]

True, but keep in mind that just about every other railgun fires a burst. I tend to think of the GB's Boom Gun as firing a 'burst' all at once instead of over a second or two.

(And I agree with jaymz... just make it a slug.)

redone as a slug (and in fact, the same for the vast majority of railguns) would be fine with me.

and most railgun ammo isn't really described... but at least i can presume a railgun is using ammunition(smaller than would be found in a slug-throwing boom gun obviously) designed for penetrating armour. flechettes are not used for penetrating armour.

Actually I allow machine gun style "railguns" as rail gun sounds cooler than coil gun but I also have rail cannons. C-40R = Railgun, RG-14 = Rail Cannon.

[glitterboy2098]

and actually Flechettes were created to penetrate armor.. they were developed because infantry bodyarmor started being able to stop the pellets in shotguns, so the idea of firing narrow cross section darts packed together in a sabot housing was developed. the darts had greater armor penetration than round pellets, and actually scattered less than the equivalent mass of shot due to being ore aerodynamic. the reason infantry scale weapons ceased using them was mainly cost. it was cheaper to buy regular shot rounds than to have Flechette rounds made. especially since you could fit more shot into a shell than fletchettes. large weapons still use them in antipersonnel warheads.. they work better than plain shrapnel or round shot when used in air burst artillery, and their reduced spread over longer range makes them more useful in large direct fire applications.

i would point out too that the "SLAP" round, or 'sabot light armor penetrator' is basically just a Flechette replacing a standard bullet.. they tend to be lighter than conventional bullets of similar length, and thus can reach higher velocities, leading to better penetration.

[Shark_Force]

better than a ball is not the same thing as armour-piercing. they replaced shot, not armour-piercing bullets.

the SLAP is a larger version of a flechette. given that flechette means small dart, it is no longer a flechette, on account of no longer being a small dart any more, but more of an average sized one.

furthermore, they are *light* armour piercing. used for lightly armoured vehicles and aircraft. now, i'll be honest, i don't know a huge amount about the armour on lightly armoured vehicles, or on aircraft... but i don't think i've ever head anyone describe aircraft as really being an armoured target at all. probably used their for the accuracy provided by fins? well, that and the fact that higher velocity means you can get away with leading less.

and precisely what a lightly armoured vehicle would be, i don't know. are we talking APC? armoured car? regular car with bullet-proof windows or equivalent? construction vehicle with bulletproof windows? if they're used for APCs i'd be pretty impressed. if they're just used on slightly modified armoured cars and such, not so impressed.

[Killer Cyborg]

better than a ball is not the same thing as armour-piercing. they replaced shot, not armour-piercing bullets.

What do you think that "armor-piercing" entails, design-wise?

[Zamion138]

'Slap" rounds i belive can go through armor on NATO apc's but not up armored strikers, probaly on old strikers im guesing as the guy i asked did not mention them.
An armored suv or humvie id assume they would penetrate, but probaly nothing to a tank, in so much as yeah its doing more than a .50 but were still not talking worth your time to try.

This was explained to me when i asked a friend on facebook who was in the army but i did not reserch it. Then again he has no reason to fib about it either i suppose

[glitterboy2098]

keep in mind that the increased crit range with high level HTH skills only applies to melee combat, not ranged. (at least, AFAIK)

[Shark_Force]

better than a ball is not the same thing as armour-piercing. they replaced shot, not armour-piercing bullets.

What do you think that "armor-piercing" entails, design-wise?

having heard a bit more about it, i'd probably allow it the armour piercing rules vs most personal body armour, and MDC vehicles that aren't specifically heavily armoured (at least, presuming we're talking MD SLAP rounds as opposed to standard SDC ones, which if they won't do anything to a tough SDC APC aren't going to do anything to a suit of body armour that probably makes some modern tank armour look like improvised scrap armour).

but arguably, any bullet is armour-piercing to some extent or another.

and in the case of flechettes specifically, like i said: it was designed to replace shot. it wasn't used to replace standard ammunition, it was just better than shooting someone with a shotgun loaded with standard pellets. better at penetrating armour than a weapon that is probably the worst at penetrating armour around (at least, in terms of firearms) is not a strong recommendation.

[glitterboy2098]

and yet the Fletchettes used for SLAP ammo, which does replace regular bullets, is the same design as the ones used in shotguns.
so yes, Fletchettes are much better at penetrating armor than regular bullets.

for that matter, an APFSDS round for tank cannon, bar none the best at beating armor, is a scaled up fletchette.

Fletchettes are better at beating armor because they concentrate all their kinetic energy onto a small point. smaller than even regular "pointy" bullets. and because thy are generally made from materials lighter than the round shot or regular pointy bullets they are replacing, their velocity is higher (generally meaning more kinetic energy, because of the way 1/2M*V^2 works out..)

[flatline]

I think you guys are getting derailed.

The issue isn't whether or not a flechette or a slug or whatever is better at penetrating armor. The issue is whether a single projectile (flechette, slug, whatever) with mass X is better than multiple smaller but ultimately identical projectiles with combined mass X at penetrating armor.

And the answer, of course, is "yes". And this is the correct answer no matter what type of projectile we're talking about as long as we're firing said projectile in an atmosphere. (And it's probably true even if you're in a vacuum, although the proof is different).

--flatline

[Shark_Force]

and because thy are generally made from materials lighter than the round shot or regular pointy bullets they are replacing, their velocity is higher (generally meaning more kinetic energy, because of the way 1/2M*V^2 works out..)

errr... no. energy in equals energy out. their velocity is undoubtedly higher due to less mass, but that doesn't magically increase kinetic energy. the kinetic energy will be the same. the shape of the round, the toughness of the material, etc will alter the results of the collision, but if you cut mass in half you don't get to double the velocity. that kinetic energy equation works both ways, and unless you put more energy in (or increase efficiency of energy transferred to the round) you are not going to increase kinetic energy just by propelling a smaller mass. physics doesn't work that way.

for example, if we have a very nice, simple, v = 2, m = 2, we can calculate the kinetic energy imparted by the explosion:

E = 1/2 m * v ^ 2
E = 1/2 (2) * (2) ^ 2
E = 1 * 4
E = 4

we now have the kinetic energy. if you use the same explosive force to propel a lesser mass, here's what *actually* happens:

E = 1/2 m * v ^ 2

now, we know that E = 4. the explosion that hurled our mass was identical, therefore, there is no increase in the kinetic energy. 1/2 of the original mass is 1, so substituting in:

4 = 1/2 (1) * v ^ 2
4 = 1/2 v ^ 2
8 = v ^ 2
v = sqrt(8)
v = ~ +/- 2.83

(in this case, we can ignore the negative value)

cut the mass in half, and you actually only get a velocity increase of about 41%, or ~1.41 times the velocity (the actual specific value of the velocity increase is the square root of 2, actually, which if i'd taken the time i could probably have demonstrated that will always be the result of dividing the mass by 2 without doing anything to increase the kinetic energy)

(in particular, i'm pretty sure that the velocity increase will always equal the square root of the inverse of the mass, but am too lazy to bother doing the math to check on that)

[flatline]

No, you're applying the math wrong. The mistake you're making is that you assume the energy imparted to the projectile is constant.

It's not.

The force used to accelerate the projectile is what is constant and since force = mass * acceleration, a less massive projectile will be accelerated more by the same force.

Let's start with a force of 100 and a mass of 2:
F = m * a
100 = 2 * a
a = 50

The kinetic energy is
.5m + v * v = .5*2 + 50*50 = 2501

If we cut the mass in half:
F = m * a
100 = 1 * a
a = 100

The kinetic energy is
.5m + v * v = .5 * 1 + 100 * 100 = 10000.5

That's 4 times the kinetic energy imparted if you apply the same force to a projectile half as massive!

--flatline

[flatline]

Admittedly, in the case of firearms, for the force to be constant assumes some things that aren't strictly true in real life. However, the force applied to the less massive projectile is reduced linearly, but since the kinetic energy goes up with the square of the velocity, the energy imparted is still greater.

To demonstrate this, let's assume that only 80% of the force gets applied to the less massive projectile:

F = ma
80 = 1a
80 = a

E = .5m + v*v = .5 * 1 + 80 * 80 = 6400.5 which is still significantly greater than 2501.

This is why real life flywheel energy storage devices are all being built to weigh very little but spin extremely fast compared to yesterday's flywheels which were really massive but spun significantly slower (so as not to fly apart).

--flatline

[kronos]

True, but keep in mind that just about every other railgun fires a burst. I tend to think of the GB's Boom Gun as firing a 'burst' all at once instead of over a second or two.

(And I agree with jaymz... just make it a slug.)

redone as a slug (and in fact, the same for the vast majority of railguns) would be fine with me.

and most railgun ammo isn't really described... but at least i can presume a railgun is using ammunition(smaller than would be found in a slug-throwing boom gun obviously) designed for penetrating armour. flechettes are not used for penetrating armour.

Actually, in Rifter 54, under the New Chillicothe article, page 57, Railgun Ammunition part.. The Coalition uses ball bearing type ammunition, while Northern Gun uses a ring style, and NGR uses spikes, which allows the NGR to use DU and U rounds much easier than any of their North American counterparts (due to DU/U rounds are required to be made in a more spike or bullet shape to work properly, while CS and NG would require slight modifications to fire the necessary modded rounds).
There are several 'standard sizes' for the rounds (used by everyone who makes railguns), which is measured in grains (we use this system today), although the actual physical sizes vary slightly between the different manufacturers.

[Zamion138]

True, but keep in mind that just about every other railgun fires a burst. I tend to think of the GB's Boom Gun as firing a 'burst' all at once instead of over a second or two.

(And I agree with jaymz... just make it a slug.)

redone as a slug (and in fact, the same for the vast majority of railguns) would be fine with me.

and most railgun ammo isn't really described... but at least i can presume a railgun is using ammunition(smaller than would be found in a slug-throwing boom gun obviously) designed for penetrating armour. flechettes are not used for penetrating armour.

Actually, in Rifter 54, under the New Chillicothe article, page 57, Railgun Ammunition part.. The Coalition uses ball bearing type ammunition, while Northern Gun uses a ring style, and NGR uses spikes, which allows the NGR to use DU and U rounds much easier than any of their North American counterparts (due to DU/U rounds are required to be made in a more spike or bullet shape to work properly, while CS and NG would require slight modifications to fire the necessary modded rounds).
There are several 'standard sizes' for the rounds (used by everyone who makes railguns), which is measured in grains (we use this system today), although the actual physical sizes vary slightly between the different manufacturers.

While im not saying this to you but that makes no sense, ball bearings and disks are not great striking surfaces and you cant stack as many in a small place, due to the gaps air between them. Spikes/pegs yeah you can tighter pack them and as a weapon it makes more sense as a striking surface.

Also for rings thats not nearly as aerodynamic as a spike or ball.

[jaymz]

How is a flat disc/ring not aerodynamic?

[Zamion138]

There is a reason no modern weapon system uses them.
for starters yeah a flat disk would fly good but any cross draft would throw them off course pretty easy, also for point of fact i was envisioning them flying out like an O not as a frisbee so disregard that half ........... yeah flat wise better than O wise....still id say its mostly cool sounding and less effective than a spike or bullet shape.

[jaymz]

A cross draft could just as easily throw off a spike too if not easier since a spike would likely have more of a side cross section than a ring might

[Shark_Force]

No, you're applying the math wrong. The mistake you're making is that you assume the energy imparted to the projectile is constant.

It's not.

The force used to accelerate the projectile is what is constant and since force = mass * acceleration, a less massive projectile will be accelerated more by the same force.

Let's start with a force of 100 and a mass of 2:
F = m * a
100 = 2 * a
a = 50

The kinetic energy is
.5m + v * v = .5*2 + 50*50 = 2501

If we cut the mass in half:
F = m * a
100 = 1 * a
a = 100

The kinetic energy is
.5m + v * v = .5 * 1 + 100 * 100 = 10000.5

That's 4 times the kinetic energy imparted if you apply the same force to a projectile half as massive!

--flatline

interesting... where does the extra kinetic energy come from?

(this is a legitimate question, btw... the kinetic energy has to come from somewhere, since you can't just create it from nothing. does this just mean the vented gasses are going slower because they imparted more of their energy? obviously, the explosion would contain the same amount of energy in either case, so if we're giving away more kinetic energy, the energy has to come from somewhere, and where that somewhere is, is something i'm having a problem with figuring out...)

[Killer Cyborg]

How is a flat disc/ring not aerodynamic?

Hard to make them fly straight. That's why frisbees and aerobes have to be specially shaped, and even then, they don't fly in straight lines.

Of course, considering the hit-ratio of rail-gun rounds, it only makes sense that they'd be using discs, rings, balls, and other less-than-ideal shapes.

[kronos]

True, but keep in mind that just about every other railgun fires a burst. I tend to think of the GB's Boom Gun as firing a 'burst' all at once instead of over a second or two.

(And I agree with jaymz... just make it a slug.)

redone as a slug (and in fact, the same for the vast majority of railguns) would be fine with me.

and most railgun ammo isn't really described... but at least i can presume a railgun is using ammunition(smaller than would be found in a slug-throwing boom gun obviously) designed for penetrating armour. flechettes are not used for penetrating armour.

Actually, in Rifter 54, under the New Chillicothe article, page 57, Railgun Ammunition part.. The Coalition uses ball bearing type ammunition, while Northern Gun uses a ring style, and NGR uses spikes, which allows the NGR to use DU and U rounds much easier than any of their North American counterparts (due to DU/U rounds are required to be made in a more spike or bullet shape to work properly, while CS and NG would require slight modifications to fire the necessary modded rounds).
There are several 'standard sizes' for the rounds (used by everyone who makes railguns), which is measured in grains (we use this system today), although the actual physical sizes vary slightly between the different manufacturers.

While im not saying this to you but that makes no sense, ball bearings and disks are not great striking surfaces and you cant stack as many in a small place, due to the gaps air between them. Spikes/pegs yeah you can tighter pack them and as a weapon it makes more sense as a striking surface.

Also for rings thats not nearly as aerodynamic as a spike or ball.

I'm not agreeing or disagreeing that it makes sense. Just mentioning that the ammunition is described, when you mentioned they were not really described. Also they're usually made from tungsten with a jacket made from some sort of magnetic polymer (I forget exactly what it's made of as I don't have the book open at the moment) that quickly burns off within a couple of seconds of being fired. Whether it makes sense or not, it's what's Palladium uses for their railgun rules for different manufacturers.

[glitterboy2098]

and because thy are generally made from materials lighter than the round shot or regular pointy bullets they are replacing, their velocity is higher (generally meaning more kinetic energy, because of the way 1/2M*V^2 works out..)

errr... no. energy in equals energy out. their velocity is undoubtedly higher due to less mass, but that doesn't magically increase kinetic energy. the kinetic energy will be the same. the shape of the round, the toughness of the material, etc will alter the results of the collision, but if you cut mass in half you don't get to double the velocity. that kinetic energy equation works both ways, and unless you put more energy in (or increase efficiency of energy transferred to the round) you are not going to increase kinetic energy just by propelling a smaller mass. physics doesn't work that way.

momentum (p= M*V) remains constant.
but kinetic energy (1/2*M*V^2) varies.

your kinetic energy goes up much faster than your momentum when you increase speed (remember, in KE it's half the square of the velocity, rather than just the velocity. so while velocity might be going from 2 to 4, doubling the momentum, while for kinetic energy it's going from 2 to 0.5*4^2,or a result of 8. quadrupling the kinetic energy. mass changes have a much lesser change when it comes to Kinetic energy. halve the mass, and double the velocity, and you can get lots more KE)

the difference is vector vs scalar. momentum is a directional thing, the energy measured from its movement. but kinetic energy is the total energy of the system, only some of which is expressed as movement. when an object hits something, it is the amount of kinetic energy, not the amount of momentum, which governs what the effects of the impact are.

here is a primer that can help explain: http://batesvilleinschools.com/physics/ ... entum.html
http://en.wikipedia.org/wiki/Kinetic_energy
http://en.wikipedia.org/wiki/Momentum

[flatline]

No, you're applying the math wrong. The mistake you're making is that you assume the energy imparted to the projectile is constant.

It's not.

The force used to accelerate the projectile is what is constant and since force = mass * acceleration, a less massive projectile will be accelerated more by the same force.

Let's start with a force of 100 and a mass of 2:
F = m * a
100 = 2 * a
a = 50

The kinetic energy is
.5m + v * v = .5*2 + 50*50 = 2501

If we cut the mass in half:
F = m * a
100 = 1 * a
a = 100

The kinetic energy is
.5m + v * v = .5 * 1 + 100 * 100 = 10000.5

That's 4 times the kinetic energy imparted if you apply the same force to a projectile half as massive!

--flatline

interesting... where does the extra kinetic energy come from?

(this is a legitimate question, btw... the kinetic energy has to come from somewhere, since you can't just create it from nothing. does this just mean the vented gasses are going slower because they imparted more of their energy? obviously, the explosion would contain the same amount of energy in either case, so if we're giving away more kinetic energy, the energy has to come from somewhere, and where that somewhere is, is something i'm having a problem with figuring out...)

There isn't any "extra" energy. Both energy and momentum must be conserved. It's just that the less massive projectile accepts a larger portion of the energy present in the whole system than the more massive projectile will.

This is confusing because while we tend to equate applying a force to something with transferring energy to it, force and energy are not related that way. For instance, if you're lying on the ground, the Earth is applying a force equal to your weight to you, yet no energy is being transferred. Energy is only transferred if work is being done.

So the real question is where is that energy going when you have a more massive projectile if it isn't going into the projectile? I can't give a definitive answer to that. Some energy is spent heating the chamber, barrel, and projectile. Some energy is spent accelerating the gun backwards (aka recoil). I'm sure there are other energy sinks in the system, but I would imagine these are the two dominant. Thermodynamics is not one of my strong fields, so maybe someone with a more thorough understanding can give a better explanation (and correct anything that I may have gotten wrong).

My gut tells me that the interaction between conservation of momentum and conservation of energy dictates how much kinetic energy can be transferred to the projectile, but I don't know how to examine that mathematically to see if it's true. If true, that may have an interesting consequence that the same mass bullet with the same amount of propellant might have more or less kinetic energy imparted to it if you vary the mass of the gun without changing anything else. I think this is intuitive since a heavier gun will experience less recoil (and thus drain less kinetic energy). But again, I don't know how to demonstrate it mathematically.

--flatline

[jaymz]

Simple question then...

If Mass A projectile is fired at B velocity = C force of impact, then does Mass 1/2 A projectile fired at 2 B velocity = C force of impact? Or does it equal some fraction lower or higher than C force of impact?

I do not know the answer myself which is why I am asking.

[glitterboy2098]

mathematically, no. 1/2 the mass and twice the velocity does not equal the same force of impact.

velocity 4m/s and mass 4kg = 16 newton seconds of momentum, and 32 joules of kinetic energy.

velocity 8m/s and mass 2kg = 16 newton seconds of momentum, and 64 joules of kinetic energy.

the joules of kinetic energy define the force of impact. the newton seconds of momentum define how hard it is to get it up to that velocity.

[jaymz]

mathematically, no. 1/2 the mass and twice the velocity does not equal the same force of impact.

velocity 4m/s and mass 4kg = 16 newton seconds of momentum, and 32 joules of kinetic energy.

velocity 8m/s and mass 2kg = 16 newton seconds of momentum, and 64 joules of kinetic energy.

the joules of kinetic energy define the force of impact. the newton seconds of momentum define how hard it is to get it up to that velocity.

So theoretically the lighter projectile should impart twice the force at impact and thus twice the damage? Good to know.

[flatline]

mathematically, no. 1/2 the mass and twice the velocity does not equal the same force of impact.

velocity 4m/s and mass 4kg = 16 newton seconds of momentum, and 32 joules of kinetic energy.

velocity 8m/s and mass 2kg = 16 newton seconds of momentum, and 64 joules of kinetic energy.

the joules of kinetic energy define the force of impact. the newton seconds of momentum define how hard it is to get it up to that velocity.

So theoretically the lighter projectile should impart twice the force at impact and thus twice the damage? Good to know.

I'm uncomfortable with the term "force of impact". The second projectile has twice the kinetic energy with which to do work on the target, so it has the potential to do twice the damage.

I am careful to say "potential to do twice the damage" because it may simply blow through the target and transfer a fraction of it's kinetic energy to the target. I think the term for this is "over penetrate".

--flatline

[jaymz]

mathematically, no. 1/2 the mass and twice the velocity does not equal the same force of impact.

velocity 4m/s and mass 4kg = 16 newton seconds of momentum, and 32 joules of kinetic energy.

velocity 8m/s and mass 2kg = 16 newton seconds of momentum, and 64 joules of kinetic energy.

the joules of kinetic energy define the force of impact. the newton seconds of momentum define how hard it is to get it up to that velocity.

So theoretically the lighter projectile should impart twice the force at impact and thus twice the damage? Good to know.

I'm uncomfortable with the term "force of impact". The second projectile has twice the kinetic energy with which to do work on the target, so it has the potential to do twice the damage.

I am careful to say "potential to do twice the damage" because it may simply blow through the target and transfer a fraction of it's kinetic energy to the target. I think the term for this is "over penetrate".

--flatline

That may be true in real life but as it pertains to the palladium system it is essentially "twice the damage" I would think.

[glitterboy2098]

theoretically. by the math yes, but there are lots of real world things that can effect it. a lighter projectile is generally going to be more susceptible to things like friction, wind, tumbling, etc that can alter its velocity and effect how it hits (for example, rifling puts some of the momentum into spin, which can reduce velocity.. one reason APFSDS rounds are generally only used in smoothbores)

and while the force might be the same, the blast effect on impact can vary depending on the density of the projectile.. less dense materials tend to just expend their energy upon impact, while denser materials can sometimes hold together longer and impart more of the energy into the target (better penetration) rather than creating the impact shockwave. this is one reason that APFSDS and SLAP rounds use subcalibre projectiles and sabots rather than just making their darts as big as the regular rounds.. it lets them use the denser materials with better penetration characteristics.



on force of impact.. above 1.5 kilometers per second (1500m/s, or about mach 7, the velocity of modern tank guns) the impactor will flash to plasma spray upon impact due to the energy release. can occur to a lesser degree at slower speeds.
the faster the impact, the more energetic the result at impact. it's not so much the round doing the damage as it is the superfast super hot cloud of metal vapor punching through.

pnenetration depends a lot on how you build your projectile. build it one way it just punches a hole in one side of the target and sprays the inside with burning metal. build it another way, and in theory the outer part of the projectile will turn into a plasma sheath that lets an inner core punch through farther. though no one has managed to figure out the exact design for the latter..

[flatline]

mathematically, no. 1/2 the mass and twice the velocity does not equal the same force of impact.

velocity 4m/s and mass 4kg = 16 newton seconds of momentum, and 32 joules of kinetic energy.

velocity 8m/s and mass 2kg = 16 newton seconds of momentum, and 64 joules of kinetic energy.

the joules of kinetic energy define the force of impact. the newton seconds of momentum define how hard it is to get it up to that velocity.

So theoretically the lighter projectile should impart twice the force at impact and thus twice the damage? Good to know.

I'm uncomfortable with the term "force of impact". The second projectile has twice the kinetic energy with which to do work on the target, so it has the potential to do twice the damage.

I am careful to say "potential to do twice the damage" because it may simply blow through the target and transfer a fraction of it's kinetic energy to the target. I think the term for this is "over penetrate".

--flatline

That may be true in real life but as it pertains to the palladium system it is essentially "twice the damage" I would think.

Well, damage in the Palladium system isn't linear, so I'd be careful. For instance, a .30 rifle does 5d6 SDC and a .50 rifle does 7d6 SDC, but the .50 has way more than twice the energy of the .30 even though it only does 2d6 more damage.

--flatline

[jaymz]

The why bother even discussing real world physics at all in this thread if we can apply it properly to begin with?

[Zamion138]

mathematically, no. 1/2 the mass and twice the velocity does not equal the same force of impact.

velocity 4m/s and mass 4kg = 16 newton seconds of momentum, and 32 joules of kinetic energy.

velocity 8m/s and mass 2kg = 16 newton seconds of momentum, and 64 joules of kinetic energy.

the joules of kinetic energy define the force of impact. the newton seconds of momentum define how hard it is to get it up to that velocity.

So theoretically the lighter projectile should impart twice the force at impact and thus twice the damage? Good to know.

I'm uncomfortable with the term "force of impact". The second projectile has twice the kinetic energy with which to do work on the target, so it has the potential to do twice the damage.

I am careful to say "potential to do twice the damage" because it may simply blow through the target and transfer a fraction of it's kinetic energy to the target. I think the term for this is "over penetrate".

--flatline

That may be true in real life but as it pertains to the palladium system it is essentially "twice the damage" I would think.

Well, damage in the Palladium system isn't linear, so I'd be careful. For instance, a .30 rifle does 5d6 SDC and a .50 rifle does 7d6 SDC, but the .50 has way more than twice the energy of the .30 even though it only does 2d6 more damage.

--flatline

And it depends on the source to, some. 50cals do 6d6 some do 1d4x10 and i cant remember where but iswear some do 1d6x10.
Palladium and I do not see eye to eye when it comes to conventional weaponry.

[flatline]

The why bother even discussing real world physics at all in this thread if we can apply it properly to begin with?

Because it's important to train your intuition against how things work in the real world.

--flatline

[jaymz]

The why bother even discussing real world physics at all in this thread if we can apply it properly to begin with?

Because it's important to train your intuition against how things work in the real world.

--flatline

I don't see why if in the game world that real world intuition is not relevant. And we are seeing here that it isn't so why continue discussing real world physics as it pertains to A/P missiles/ammo in a Palladium game? We know the guns aren't portrayed accurately and unless we are going to rewrite the entire weapon lines arguing/discussing all of this is just an exercise in futility and pointlessness. In other words how about we all get back on to the topic of the actual thread?

[Shark_Force]

The why bother even discussing real world physics at all in this thread if we can apply it properly to begin with?

Because it's important to train your intuition against how things work in the real world.

--flatline

I don't see why if in the game world that real world intuition is not relevant. And we are seeing here that it isn't so why continue discussing real world physics as it pertains to A/P missiles/ammo in a Palladium game? We know the guns aren't portrayed accurately and unless we are going to rewrite the entire weapon lines arguing/discussing all of this is just an exercise in futility and pointlessness. In other words how about we all get back on to the topic of the actual thread?

what is there about:

Has anything every been added to any book where weapons described as Armor Piercing have a use? Usually they're lower damage weapons with a smaller blast radius. While that doesn't inherently bother me, i'm curious to know if there were ever further rules on what value AP rounds/missiles have.

that you feel is unresolved?

@ flatline: i know the energy isn't extra in the sense of coming from nowhere... but as we both know, it must come from somewhere. the "extra" energy i was referring to, is the extra energy carried by the lighter projectile as compared to the heavier one... it has to have come from somewhere else in the system. i'm just trying to make it work in my head where i can figure out what else would have gained less energy.

(also, i'm pretty sure heavier guns actually only have less "felt" recoil... ie, because they are heavier, they accelerate less, so it doesn't feel like they recoil as much even though the total recoil is the same. could be wrong on that one, though).

[jaymz]

Point being the real world physics isn't applicable and pretending it does and arguing about it is pointless and not really what this thread is about

[Shark_Force]

Point being the real world physics isn't applicable and pretending it does and arguing about it is pointless and not really what this thread is about

point being, the thread was resolved quite some time ago, and at this point, it doesn't much matter what's being discussed anyways.

if you feel that there is something unresolved from the purpose of the thread, we can discuss that. otherwise... well, a discussion on the RL physics and how the game world would work if such were applied to this discussion is at least as relevant as anything else.