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I don't understand how you can understand this part:

Grey Templar wrote:Well, the way to damage something is to transfer energy from once place to another. i put Kinetic energy into my club, club transfers energy to your skull, your skull gains kenetic energy and goes flying.

And then totally miss the ball with this part

Grey Templar wrote:Also Railguns don't have recoil either...

For every action there is an equal and opposite reaction. Using electricity and/or magnetism to accelerate a round is no different than using an explosive charge like gun powder as seen from the firer's perspective. As long as your gun obey the laws of physics it means whatever amount of energy your delivering on target the gun is also delivering back into firer plus some.

Melissia wrote:The standard mars-pattern Autogun (again, the most generic you can get) would cost a civilian 100 thrones to obtain. Including a single full clip / full battery of ammunition, this increases to 90 / 101.5 thrones, respectively.

Lets put all that aside and place ourselves directly in the boots of some far flung imaginary quartermaster general. We are arming and outfitting an entire army going off to some war that will take years for your supplies and troops to get to. You have a limited number of ships, and a limited amount of room, into which you need to stuff the maximum amount of "kill-ability" as you feasibly can. Even IF traditional ammunition was cheaper to make and more powerful in use, its taking up a room in your transport and it represents only 1 shot. If a box of lasgun battery packs represents multiple orders of magnitude more shots and takes up the same volume as a box of slug rounds in your transport, AND the lasgun doesn't need resupply (excepting breakage, etc), could you afford NOT to arm them with lasguns?

You have a choice of sending:
50 ships of soldiers and slug guns w/ ammo that you also have to resupply; or
1 ship of the same number of soldiers and the same number of weapons with 100 times more ammo and no resupply commitment (both necessitate food, water, clothes, replacement parts, etc so we are ignoring that bit).

It's pretty obvious what the right choice is...

You claim railguns have recoil.

the "equal and opposite reaction" part of a railgun is the opposite magnetic force that the slug exherts upon the 2 rails. the opposite reaction is reversed and propels the slug even faster. the slug is actually never in contact with the barrel as it is levitating in the chamber.

however, that exhertion will not translate into a force from the gun to whatever it is mounted on or being carried by.

also the rails exhert such an intense force on each other that the gun must be tightly bound together(this will reduce, if there is any, recoil by a massive factor)


any actual recoil will be so small that it will not translate into a force that would effect its wielder.



Railguns not having a kick doesn't defy the laws of physics, it puts them to use in new and interesting ways.

Railgun does have recoil. They did experiments with a railgun mounted on an M551 Sheridan, and found that on light tanks, firing high caliber rail-based weapons caused far too much recoil.

http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA387401

Grey Templar wrote:the "equal and opposite reaction" part of a railgun is the opposite magnetic force that the slug exherts upon the 2 rails. the opposite reaction is reversed and propels the slug even faster. the slug is actually never in contact with the barrel as it is levitating in the chamber. however, that exhertion will not translate into a force from the gun to whatever it is mounted on or being carried by.

Nope. Think of it like this, if I push on you we both get pushed, but in opposite directions. If we are holding magnets and I push on you, the exact same thing happens regardless of if I ever actually physically touch you or not.

Grey Templar wrote:also the rails exhert such an intense force on each other that the gun must be tightly bound together (this will reduce, if there is any, recoil by a massive factor) any actual recoil will be so small that it will not translate into a force that would effect its wielder.

"The barrel blowing up is bad" OK sure, makes sense. "A barrel that doesn't blow up reduces recoil" Ummm... Huh?

Grey Templar wrote:Railguns not having a kick doesn't defy the laws of physics, it puts them to use in new and interesting ways.

I'll admit it's a novel way to push a round down range, but keep in mind that's all it is, pushing a bullet down range. If you were in space holding a railgun and you shot a bullet with the same mass as the gun and yourself together, you and the bullet would travel in opposite directions from each other with the same velocity. Force isn't one directional. Objects either pull each other together, or push each other apart, the only difference is mass determines which moves more. If a bullet is delivering some amount of force down range to your target, regardless of how you sent it there, it has already delivered that same amount of force back into the firer + the loses of air resistance over the flight of the bullet.

I think I might know whats probably confusing you though, in a Gauss or Coil gun the magnetic coils are always in front of the round pulling it forward. It seems like this would if anything pull the gun forward canceling out recoil. What really happens though, and you can see this for yourself in a swimming pool with a friend, is pulling an object away from you exerts the same bi-direction force as pushing an object does. The place your exerting the force at has perspectively rotated 180 degrees, but so has the direction in which your exerting the force.

Grey Templar wrote:There is no force pushing backwards in a Railgun. its magnetic acceleration.

So, magnetic force only works one way? If I use a magnet to lift a big weight it pulls the weight up but does not pull the magnet down?

Incorrect.

Recoil for a railgun is exactly the same as any other kinetic weapon.

It's worth noting, that for the purposes of fighting against armoured opponents, ballistic weaponry is probably better. Las weapons that don't penetrate completely will do no damage, while ballistic weapons at least have some stopping power that armour can't always protect against (ie, you could be wearing a bulletproof vest, but if you get shot, you're probably going to fall down, and maybe even bruise, even if the bullet doesn't actually penetrate, where as a lasgun that gets stopped by armour would do no damage to any layers underneath).

This is an excellent point and something that is either not adressed or abstracted away in most wargames and RP systems.

I do recall a system that had two damage value for weapons - one that was reduced by your armour and a second that you took either way. So, a saber bouncing off your helmet does almost no damage, a big two-handed axe hurts like hell even if the helmet does stop it. Even with the best powered armour in the game a 30mm multi-barrel cannon killed you stone dead with one burst even though it couldn't pierce your armour.

A laser hit would cause a localised explosion which would create a shockwave possibly capable of travelling through the armour and creating damage on the inside by pressure or spalling.

Or maybe not. I have no idea if a bullet or a laser joule for joule would be better at doing this.

I expect if laser weapons became practical armour would be developed to guard against them. For example, an ablative layer over a reflective layer backed by a superconductor layer to carry the heat away.

Chongara wrote:The physics of 40k are held together by Duct Tape, Rule of Cool and the light reflected off bald heads.

I almost died from laughter when reading this.

S_P

From what I can gather from the fluff (mostly from Necromunda) Only SM's can use and maintain Bolt weapons to a high standard.

Soild Ammo good in terms of being stronger and getting past armour is generally agreed through out the 40K fluff.

That being said Dark Heresy and Necromunda do not represent the entire Imperium of Man.

Different worlds, Different wars, Different weapons.

Karvick wrote:From what I can gather from the fluff (mostly from Necromunda) Only SM's can use and maintain Bolt weapons to a high standard.

Marines, Sororitas, and the Inquisition. The latter two have more resources at their disposal than the Marines do, actually, due to the power and money of the Ecclesiarchy and the authority of the Inquisition.

Kilkrazy wrote:I expect if laser weapons became practical armour would be developed to guard against them. For example, an ablative layer over a reflective layer backed by a superconductor layer to carry the heat away.

You would get passable cheap protection by having a copper layer somewhere in the sandwich (to conduct and hence dissapate the absorbed heat)

Though I don't like repeating myself verbatim, lasguns don't fire lasers, they fire lasbolts. What exactly these are I don't know, but someone suggested they're basically like really weak versions of tau plasma (I don't know where they got that information).

Lasbolt probably is just what the ignorant, superstitious IG soldiers call it.

Anyway, if it's a plasma pulse it still relies on electrical energy to create the pulse and light and heat absorption to create damage in the target, so we can still make a comparison with bullets.

Besides, remember, flak armor is actually designed for both solid and energy weapons.

Aren't there mentions of cleaning the lenses in the fluff?

The Imperial Infantryman's Uplifting Primer does not mention cleansing the lenses. It mentions cleansing the "ignition rings".

This is supposed to be a literal translation of the Primer issued to Guardsman, so this is some pretty solid fluff.

It's also listed as having a full auto mode capable of delivering 220 shots per minute (3.67 shots per second).

Melissia wrote:The Imperial Infantryman's Uplifting Primer does not mention cleansing the lenses. It mentions cleansing the "ignition rings".

Spot the homoerotic subtext.

Melissia wrote:
This is supposed to be a literal translation of the Primer issued to Guardsman, so this is some pretty solid fluff.

It's also listed as having a full auto mode capable of delivering 220 shots per minute (3.67 shots per second).

That's quite a low cyclic rate of fire. Modern guns have an RoF ranging from about 400 up to 1,200 depending on design. (Electrically driven guns can go up to 10,000 rpm but they are not man-portable.)

Yes, but keep in mind that this is probably limited in order to prevent damage to the barrel due to overheating.

Ordinary rifles aren't intended to be fired that much, however heavy machine guns are equipped with changeable barrels and water jackets to enable them to fire sustainably.

There is a case of a British machine-gun company in WW1 which fired its 10 Vickers guns in indirect fire mode continuously for 12 hours. They shot a million rounds, changed 100 barrels and did not suffer a single breakdown.

Grey Templar wrote:There is no force pushing backwards in a Railgun. its magnetic acceleration. No gas compression = no recoil.

there is a sonic boom from the speed of the projectile, but no actual recoil.

the round goes from 0 to mach5 instantly. there is nothing that would cause a recoil.

You do understand basic Newtonian principles(not to mention basic physics), right?

For every action, there is an equal and opposite reaction....

Railguns do have recoil- in current terms its negligible because the HUGE units are fixed and firing rather small projectiles- so the mass comparison of the projectile vs the launcher is like a BB trying to move a brick.

Recoil is caused by the mass and speed(which = energy) of the projectile being launched- not the mechanics of how its launched. Thats why a 12 ga shotgun has more felt recoil, its firing a very heavy shot, vs a 5.56 NATO that fires a smaller round much faster.

So, a rail gun that weighs the same as a conventional firearm, would have very similar recoil(conventional designs can vary in recoil due to the mechanical aspects of certain design features) if the projectiles mass and velocity were the same.

I think you're confusing magnetic acceleration with antigravity theory. Some sci fi has mixed anti grav into rail guns to offset recoil. But- otherwise- you're very wrong- to quote Scotty on this one "Ye cannot deny the laws of physics "

@Melissa & KillKrazy: You guys seem to be equating effectivness to rate of fire but that doesn't change that the lasgun and autogun are equal.

We are told that the effectivness of the Lasgun at its given rate of fire is about equal to that of an autogun over the same period of time, so we can assume that shot for shot the lasgun is stronger.


Damage Over Time (DOT) = Rate of Fire (RoF) * Base Damage per shot (BD) <--- Here it is psudo-mathmatically


class weapon
{
int RoF;
int BD;
public:
int DOT(int, int);
} pewpew;

int weapon :: DOT(int a, int b)
{int Dmg;
RoF = a;
BD = b;
Dmg=BD*RoF;
return Dmg;} // <-- Here it is in C++, I'm a bored nerd and this passes for humor to me

From here think of it as algebra (gasp! the A-word!) if the DOT is about equal between the two, but the autogun has a higher RoF then the BD of the Lasgun must be higher to make up for it. Overheating, jamming, replacing parts are only factors as to why they are equal.

I'm not, I'm just pointing out that the lasgun seems strangely short of RoF considering its advantage is supposed to be having more ammo on board.

More shots thrown down range usually increases the potential of hits.

RoF is also an advantage for armour piercing. The GAU-8 cannon gains its power partly from saturating the target with a volley of rounds that smash up the armour -- this effect is represented in 40K by the REnding rule for assault cannons.

Possibly it is to prevent overheating.

Either that, or GW didn't take the time to work out how many rounds per second it would be.

S_P

I really can't imagine that GW would just make some gak up rather than do a calculation about it.

Kilkrazy wrote:I really can't imagine that GW would just make some gak up rather than do a calculation about it.

FWIW: a guardsmen carries 6 power packs and these allow him to fire a minimum of 2,000 shots(Depending on power settings)

so a single power pack has approximatly 333.33 shots in it.

this is from the Munitorim manual.


Vs a Autogun magazine that has, maybe, 20-30 rounds.

Grey Templar wrote:FWIW: a guardsmen carries 6 power packs and these allow him to fire a minimum of 2,000 shots(Depending on power settings)

so a single power pack has approximatly 333.33 shots in it.

I think I see where your going with this...
If a guardsman had 2 lasguns firing off the hip in a Rambo-esque fashion, he would get in a total of 666 shots right before he ripped a hole in the universe and time ate itself. Pretty nasty stuff.

Why is why there is a specific setting on a lasgun that say "Do NOT set to this location"

Besides the guardmen stupid enough to shoot from the him Rambo style will probably get shot by the commisar.

Rate of fire doesnt meen anything if you can defeat the armor of the target your firing it it at.

While a lasgun over a period of time may be able to do the same amount of "damage" to a target as an autocannon, it meens nothing if the damage is completly negated by armor.

For example a lasgun will never be able to destroy and vehicle with an AV in 40k. Same things true in real life. I could have an infinate amount of 5.56 or 7.62 mm ammunition and a gun that could fire continously forever and I would never relistically be able to destroy a modern tank with the gun.