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This would be much easier to resolve it you took weapons on a case-by-case basis and restricted it to man portable (or ground based, at least) weapons. Without some standards or structure for the discussion this can degenerate into a multi-page argument on lasguns alone (lasguns are just like an assault rifle! no they're not they're heat rays/30mm cannon!) I don't even want to think about bolters...

Technically a laser (or any beam weapon) can cause damage beyond the point of impact simply by delivering sufficient amounts of energy in a sufficient amount of time and in a sufficiently small area in order to simulate a HE detonation - much in the same way doomsday asteroid impacts and nuclear explosions can simulate.

Also lasers (RL lasers anyhow) work pretty badly as drilling heat rays because of their relatively poor penetration (unless you use something like x-rays or gamma rays, which is another issue entirely.) Heck if you're going to compare lasweapons to an autogun the lasgun is actually going to be *worse* in some respects because of cauterization - the target won't bleed out and inflicitng highly localized (and superficial) burns is not going to kill very efficiently compared to blowing holes in people. Whereas if your lasgun is a slicing beam weapon it may actually be MORE effective than a projectile weapon (how effective is an enemy going to be if you slice his head or legs off or bisect him at the torso?)

If your'e being technical yes mach can vary becuase speed of sound is material dependent (in water its 1.5 km/s) but in a more colloquial sense its likely meaning speed of sound in air. If it bugs ya that much think of it as a translation relative to english and earth - we know they use alot of earth-baesd conventions for time and such (time, metrics, distances, whatever.)

And for the record it was something like 6-8 times the speed of sound (in air). Deathwatch (Mark of the Xenos I think) had it at 6-10 x the speed of sound (or I may have it backawards - savage scars had it at 6-10x and DW had it at 6-8x).

I'm also pretty sure that tau railguns are described as hypervelocity before (I know they've been described as hypersonic in IA3 if not elsewhere.) which fits with that estimate as well.

MarcoSkoll wrote:
I'm not being "technical", I'm being accurate. Yes, while it's material dependent, I was talking merely about air (or its non-Terran equivalents).

The problem is that the speed of sound in air varies very heavily (primarily with temperature). Yes, it's typically taken to be about 340 m/s (its approximate value at RTP), but global climate differences mean that in different parts of the world, the speed of sound can range between less than 280 m/s and over 360 m/s.
Yes, Mach 9 would typically mean nine times the speed of sound in air, but there is no fixed speed of sound in air. As such, using Mach number as an indicator of velocity is like trying to build a cabinet using an elastic tape measure - good for a laugh, but not much else.

Unless we're talking insanely different extremes (like fighting underwater or high altitudes) I doubt it's going to make that much of a difference. By the standards of most 40K numbers, a 10-20% difference is not significant when you consider things like (for example) titan sizes which can range from 10 metres to several km, or starships that have battleships (or other warships) that can range from a mile long to tens of km long. Hell cruisers even in an 'accurate' range will be from hundreds of metres to 8 km (and thats not including the Gordon Rennie 30 km typo from Wolf Pack.)

im2randomghgh wrote:That much heat and energy would have no problem causing horrific unbalance to your metabolism, and blowing off arms is just icing.

Just how energetic do you think these weapons are, exactly? And how re they transmitting the energy to the target?

And the burns aren't superficial. Lexicanum describes lasguns as making a small explosion on impact.

Which can mean any number of things. 'explosion' does not by definition mean 'detonating explosive' or anything like. Nor does an explosion neccesarily. And the level of burn severity will depend on a.) energy involved and b.) penetraiton of the radiation involved. Most lasers in fact make lousy thermal weapons because they lack penetration (Barring something on the X-ray/gamma ray spectrum.) Particle beams on the other hand are highly penetrating.

Hell you can actually make a series of 'small' explosions with a laser that create wounds that actually duplicate gunfire with about the same magnitude of energy. Those are EFFICIENT lasers. By contrast killing by burns with lasers means affecting a rather large surface area (EG the entire torso, etc.) and eve nthen its not a very rapid kill mechanism (at least, not as fast as we see in novels and fluff.) described here

And punching holes in people doesn't do much damage, unless it is either a huge hole, or somewhere vital. That is why armour piercing rounds do such poor damage to the actual target, and why hollow point round and any round designed to fracture on impact to increase damage will cause ghastly damages to the actual target but fail hilariously against armour.

Hollowpoints are not fragmenting rounds. Hollowpoints are designed to deform on impact to increase the diameter of the bullet and hence the hole made.



here and here you have fragmenting rounds. And then there is always the chance that rounds might tumble in the wound, especially if they glance off bone. Heck, striking bone has a good chance of creating additional shrapnel in the target depending on where you hit and with that.

this link has some more examples of wound profiles from differeing kinds of weapons. It's kinda fascinating in a gruesome way.

im2randomghgh wrote:Notice how I said Hollow points and fracturing rounds? Not that Hollow points fracture?

I did now. you're correct that I missed that earlier, and I apologize.

And bullets that punch clean holes through targets are not that deadly. This is what you don't seem to be realizing. I would much, much rather be hit by an armour piercing round than a 5.56x45mm NATO round.

It depends on where they hit though, doesn't it? More to the point, what are we defining as 'small' and 'large', exactly?

And did I SAY detonating explosive? No? Then why are you talking about it?

Fine, what sort of explosion were you picturing exactly?

And then reason laser make good thermal weapons is the continuous beam they can/do produce.

So how are you picturing these hypothetical heat ray lasers killing people then?