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That's a joke post, right im2randomhghg? I don't think I've ever seen someone straw man another poster quite as badly as that. Even then, I don't think I've ever seen anyone be so condescending and arrogant at the same time.

im2randomghgh wrote:You can clearly see that this round has not just left the barrel, it has already impacted on the preset paper target, which has combusted.

There is combustion on impact, but this is entirely different to suggesting the projectile has ignited the air. Hypersonic velocities are capable of ionising air, but this is not in anyway comparable to suggesting the air has actually combusted.
"Set the air on fire" is cool prose to put into sci-fi, but it's chemically entirely wrong. The projectile itself might combust due to extreme friction from high velocity (and the air would oxidise that), but there's nothing in the air itself to burn.

As for your claimed chronology, the synchronised time codes (which are from the cameras, not post-production) don't agree with you. Impact with the paper target is at roughly 53.236, the picture as you have posted it is marked as 53.231. The wall visible in that shot is also a rather closer match to being the other side of the one we can see from the angle behind the railgun than the beam the paper target is supported from.
Sorry, but the image you gave is prior to impact with the target.

Alternatively, watch the video from two years later, where there's much less ambiguity about camera angles. The test impact occurs in the square building, but there is clearly plasma in the video of the launch (in the round tunnel).

And a railgun would have NO PROBLEM demolishing a building.

Uppercase text does not evidence make. Put a hole straight through a building, yes. Destroying it is an entirely different matter. The Rheinmetall 120mm tank gun could happily put a high velocity APDSFS round through both sides (and everything in between) of most buildings, but it takes a lot more than holing a few walls to causing structural collapse.

The railgun is indeed more energetic than the Rheinmetall, but the thing with terminal ballistics is that higher impact speeds reduce the deformation of a target material on impact. The impact lasts less time, so there's less time for the forces to transfer to and accelerate the surrounding area on the target. This is why bullets will frequently punch a neat hole through glass but a slower projectile will shatter it.
So a railgun might actually be less effective at damaging (as opposed to puncturing) walls, because the higher MV would reduce the damage to the surrounding area of wall.

In any case, one testament to the toughness of buildings is September 11th. A heavily laden 767 at over 500 miles an hour is over ten times more energetic than the US navy's railgun (And that's only if we assume the 32 MJ figure is kinetic, rather than electrical - electrical stored energy is a common measurement for electromagnetic guns), and affected a much wider area than poking a neat hole through the building. Even then, it took tonnes of aviation fuel heating and weakening the structure for nearly an hour before the first tower came down. (No conspiracy theorists please.)

This is particularly true for a building with a steel or a concrete framework, when only destroying enough of the load bearing members would have any chance of collapsing the building. Putting holes through a few walls would be entirely useless in such a building. Given the relatively small portion of the building that is load-bearing, you'd have to be lucky to hit any important parts, let alone enough to bring the building down.

MarcoSkoll wrote:Even then, it took tonnes of aviation fuel heating and weakening the structure for nearly an hour before the first tower came down. (No conspiracy theorists please.)

I saw the man flying that plane, he had green scaly skin and eyes like a snake!

You can't hide the truth!

I honestly thought the Bolter would be more like this:
http://en.wikipedia.org/wiki/Anzio_Sniper_Rifle_20mm

iproxtaco wrote:That's a joke post, right im2randomhghg? I don't think I've ever seen someone straw man another poster quite as badly as that. Even then, I don't think I've ever seen anyone be so condescending and arrogant at the same time.

The driving part was a joke.

The rest wasn't. Giving nations cart-blanche to do whatever the hell the want during wartime is a ridiculous idea. Not all the examples are temporary and small in scale like the flame-thrower: being aloud to drop nukes and anthrax at will would have much, much longer lasting effects.

im2randomghgh wrote:

iproxtaco wrote:That's a joke post, right im2randomhghg? I don't think I've ever seen someone straw man another poster quite as badly as that. Even then, I don't think I've ever seen anyone be so condescending and arrogant at the same time.

The driving part was a joke.

The rest wasn't. Giving nations cart-blanche to do whatever the hell the want during wartime is a ridiculous idea. Not all the examples are temporary and small in scale like the flame-thrower: being aloud to drop nukes and anthrax at will would have much, much longer lasting effects.

Yeah...poisoning the earth with toxic weapons wouldn't be very wise.
Now if it were in space on the other hand...

MarcoSkoll wrote:

im2randomghgh wrote:You can clearly see that this round has not just left the barrel, it has already impacted on the preset paper target, which has combusted.

There is combustion on impact, but this is entirely different to suggesting the projectile has ignited the air. Hypersonic velocities are capable of ionising air, but this is not in anyway comparable to suggesting the air has actually combusted.
"Set the air on fire" is cool prose to put into sci-fi, but it's chemically entirely wrong. The projectile itself might combust due to extreme friction from high velocity (and the air would oxidise that), but there's nothing in the air itself to burn.

As for your claimed chronology, the synchronised time codes (which are from the cameras, not post-production) don't agree with you. Impact with the paper target is at roughly 53.236, the picture as you have posted it is marked as 53.231. The wall visible in that shot is also a rather closer match to being the other side of the one we can see from the angle behind the railgun than the beam the paper target is supported from.
Sorry, but the image you gave is prior to impact with the target.

Sorry if I communicated the ignition poorly (English isn't my native language) but the air oxidizing the flaming projectile is what I meant to say.

Also, I failed to notice the time stamps, I concede it was on launch rather than impact.

im2randomghgh wrote:
The navy railgun fires much smaller rounds actually, since they do not have the magical infinity energy generators the tau have.

The Hammerhead fire's relatively small rounds judging by the barrel's actual bore size, which is relatively small (doesn't need to be huge to punch holes in tanks, unlike the ship's railguns which are designed to destroy warships and bombard beaches). In fact it's specifically referred to as a "tiny projectile" in the current Tau codex.

They also fire slower (~mach7 compared to tau mach 9) and a single railgun shot would completely wreck the whole building.

Where are you getting that speed rating for the Tau railgun? I can't find it in either the 3E or 4E codex or in IA:3.

A railgun would only wreck the building if it impacted from some sort of ballistic trajectory that would impart it's energy into the ground most likely (and even then probably not unless its projectile is a lot larger than it appears, though of course I wouldn't want to be in the house), otherwise it'd likely just go straight through and out the other side,

Lascannons would pierce all the way through the concrete, whereas the javelin got several inches only.

A Lascannon is a long range crew served/vehicle mounted energy weapon, a Javelin is a shorter ranged weapon capable of being carried and operated by a single infantryman designed for use against armor plate(just needs to make a small hole to do it's job) at relatively close ranges next to tank guns and heavier AT missiles, and not concrete, it's not an HE rocket that'd blow apart concrete effectively, though it can do something obviously. Comparing the two is silly. Especially as a thick fog or smoke/dust in all reality would drastically decrease the effectiveness of a lascannon

The lascannon would kill whoever was standing behind the cover, either forcing them get roasted or go to the window, away from the cover-smashing lascannon.

So would a 75 year old 75mm field cannon, with an actual blast to boot!

CthuluIsSpy wrote:

im2randomghgh wrote:

iproxtaco wrote:That's a joke post, right im2randomhghg? I don't think I've ever seen someone straw man another poster quite as badly as that. Even then, I don't think I've ever seen anyone be so condescending and arrogant at the same time.

The driving part was a joke.

The rest wasn't. Giving nations cart-blanche to do whatever the hell the want during wartime is a ridiculous idea. Not all the examples are temporary and small in scale like the flame-thrower: being aloud to drop nukes and anthrax at will would have much, much longer lasting effects.

Yeah...poisoning the earth with toxic weapons wouldn't be very wise.
Now if it were in space on the other hand...

Um...so you are talking about having a modified version of the Geneva convention for spatial combat?

...why?

im2randomghgh wrote:

CthuluIsSpy wrote:

im2randomghgh wrote:

iproxtaco wrote:That's a joke post, right im2randomhghg? I don't think I've ever seen someone straw man another poster quite as badly as that. Even then, I don't think I've ever seen anyone be so condescending and arrogant at the same time.

The driving part was a joke.

The rest wasn't. Giving nations cart-blanche to do whatever the hell the want during wartime is a ridiculous idea. Not all the examples are temporary and small in scale like the flame-thrower: being aloud to drop nukes and anthrax at will would have much, much longer lasting effects.

Yeah...poisoning the earth with toxic weapons wouldn't be very wise.
Now if it were in space on the other hand...

Um...so you are talking about having a modified version of the Geneva convention for spatial combat?

...why?

I am sure that if we ever manage to explore and colonize other planets, the scale of conflict would be much greater than it is today. This would, of course, mean nastier weaponry.
Of course, this is assuming that a crap-sack scenario will take place.

Vaktathi wrote:

im2randomghgh wrote:
The navy railgun fires much smaller rounds actually, since they do not have the magical infinity energy generators the tau have.

The Hammerhead fire's relatively small rounds judging by the barrel's actual bore size, which is relatively small (doesn't need to be huge to punch holes in tanks, unlike the ship's railguns which are designed to destroy warships and bombard beaches). In fact it's specifically referred to as a "tiny projectile" in the current Tau codex.

They also fire slower (~mach7 compared to tau mach 9) and a single railgun shot would completely wreck the whole building.

Where are you getting that speed rating for the Tau railgun? I can't find it in either the 3E or 4E codex or in IA:3.

A railgun would only wreck the building if it impacted from some sort of ballistic trajectory that would impart it's energy into the ground most likely (and even then probably not unless its projectile is a lot larger than it appears, though of course I wouldn't want to be in the house), otherwise it'd likely just go straight through and out the other side,

Lascannons would pierce all the way through the concrete, whereas the javelin got several inches only.

A Lascannon is a long range crew served/vehicle mounted energy weapon, a Javelin is a shorter ranged weapon capable of being carried and operated by a single infantryman designed for use against armor plate(just needs to make a small hole to do it's job) at relatively close ranges next to tank guns and heavier AT missiles, and not concrete, it's not an HE rocket that'd blow apart concrete effectively, though it can do something obviously. Comparing the two is silly. Especially as a thick fog or smoke/dust in all reality would drastically decrease the effectiveness of a lascannon

The lascannon would kill whoever was standing behind the cover, either forcing them get roasted or go to the window, away from the cover-smashing lascannon.

So would a 75 year old 75mm field cannon, with an actual blast to boot!

For bombardment, the navy would be using a special munition that break apart above it's target, giving it a wide area of effect (saw a simulation of it on youtube once, but can't find it now).

And there was brief mention of the speed in Savage Scars, Sarik estimated it moved at mach9 or so which, given the sensors in his helm, is likely accurate.

And of course it would use ballistic trajectory, why wouldn't it? Otherwise you really are wasting the massive amounts of electricity necessary.

And lol I love how you are talking down at the lascannon because it is less portable than the Javelin, and then bring a 75mm field cannon into it


Automatically Appended Next Post:

CthuluIsSpy wrote:

im2randomghgh wrote:

CthuluIsSpy wrote:

im2randomghgh wrote:

iproxtaco wrote:That's a joke post, right im2randomhghg? I don't think I've ever seen someone straw man another poster quite as badly as that. Even then, I don't think I've ever seen anyone be so condescending and arrogant at the same time.

The driving part was a joke.

The rest wasn't. Giving nations cart-blanche to do whatever the hell the want during wartime is a ridiculous idea. Not all the examples are temporary and small in scale like the flame-thrower: being aloud to drop nukes and anthrax at will would have much, much longer lasting effects.

Yeah...poisoning the earth with toxic weapons wouldn't be very wise.
Now if it were in space on the other hand...

Um...so you are talking about having a modified version of the Geneva convention for spatial combat?

...why?

I am sure that if we ever manage to explore and colonize other planets, the scale of conflict would be much greater than it is today. This would, of course, mean nastier weaponry.
Of course, this is assuming that a crap-sack scenario will take place.

I highly doubt humanity will ever have any extra-terrestrial colonies other than maybe one on the moon. Mars is nearly ideal as a planet, very similar to earth, and yet it still suffers from a thin atmosphere, 900 km/h winds, low oxygen content, most of it is too cold for human life (not all of it though, it occasionally get above 0C near the equator)

im2randomghgh wrote:
For bombardment, the navy would be using a special munition that break apart above it's target, giving it a wide area of effect (saw a simulation of it on youtube once, but can't find it now).

A heavy solid projectile can also do the job just fine, though granted I don't know much more on the specifics of what sort of projectiles they are planning or testing.

And there was brief mention of the speed in Savage Scars, Sarik estimated it moved at mach9 or so which, given the sensors in his helm, is likely accurate.

I find myself wondering when Space Marines got in-built sensors that register supersonic speeds of individual projectiles in the heat of battle Oh Black Library...

And of course it would use ballistic trajectory, why wouldn't it? Otherwise you really are wasting the massive amounts of electricity necessary.

Depends on what you're shooting at and where. If it's a direct LoS target you just want to put a hole in like a warship, or it's a close range target, probably not.

And lol I love how you are talking down at the lascannon because it is less portable than the Javelin, and then bring a 75mm field cannon into it

Because the 75mm field cannon is a much better comparison to the Lascannon, requiring a crew of 2 or 3 to transport and operate for use against targets at long range.

Vaktathi wrote:

im2randomghgh wrote:
For bombardment, the navy would be using a special munition that break apart above it's target, giving it a wide area of effect (saw a simulation of it on youtube once, but can't find it now).

A heavy solid projectile can also do the job just fine, though granted I don't know much more on the specifics of what sort of projectiles they are planning or testing.

And there was brief mention of the speed in Savage Scars, Sarik estimated it moved at mach9 or so which, given the sensors in his helm, is likely accurate.

I find myself wondering when Space Marines got in-built sensors that register supersonic speeds of individual projectiles in the heat of battle Oh Black Library...

And of course it would use ballistic trajectory, why wouldn't it? Otherwise you really are wasting the massive amounts of electricity necessary.

Depends on what you're shooting at and where. If it's a direct LoS target you just want to put a hole in like a warship, or it's a close range target, probably not.

And lol I love how you are talking down at the lascannon because it is less portable than the Javelin, and then bring a 75mm field cannon into it

Because the 75mm field cannon is a much better comparison to the Lascannon, requiring a crew of 2 or 3 to transport and operate for use against targets at long range.

1. Solid round wouldn't have the area of effect necessary for bombardment, because the electric and maintenance costs of a railgun means they can't afford to shoot a precision weapon at a large, open area.

2. BL is always good for a chuckle.

3. If you are using a railgun at close range, you have already lost in terms of maneuver warfare. The same way sniper weapon systems aren't worth gak in a CQB.

4. Well in Hell Night, Legends of the Space Marines, Trooper Genk manages the Lascannon on his own, and it seems as it his partner is merely a spotter. Meaning it could be handled by a single trooper without much difficulty. Also, lascannons are significantly smaller than 75mm cannons.

shiftystylin wrote:I thought the boltgun was supposed to fire explosive rounds at 76 caliber? Considering a Barrett 50 Cal is the most powerful "anti-material" (sniper) rifle designed to shoot through thick armour plating kinda makes a boltgun look like a really sophisticated bit of kit for a grunt to use!

And by the way, you have to be lying down to fire a Barrett 50 cal so games like CoD:MW are lying to you, no way you could fire one standing up because you'd be on the floor 10 feet behind you so to fire a 76 cal gun stood up, either the gun or the soulds would have to have great technology to counter the recoil.

To you sir I say, http://www.youtube.com/watch?v=joKVVdL81Io

Gharron wrote:

shiftystylin wrote:I thought the boltgun was supposed to fire explosive rounds at 76 caliber? Considering a Barrett 50 Cal is the most powerful "anti-material" (sniper) rifle designed to shoot through thick armour plating kinda makes a boltgun look like a really sophisticated bit of kit for a grunt to use!

And by the way, you have to be lying down to fire a Barrett 50 cal so games like CoD:MW are lying to you, no way you could fire one standing up because you'd be on the floor 10 feet behind you so to fire a 76 cal gun stood up, either the gun or the soulds would have to have great technology to counter the recoil.

To you sir I say, http://www.youtube.com/watch?v=joKVVdL81Io

You could see the weight of the rifle upsetting his balance greatly.

Then again,

http://www.youtube.com/watch?v=51CTM49rcrs

im2randomghgh wrote:

Gharron wrote:

shiftystylin wrote:I thought the boltgun was supposed to fire explosive rounds at 76 caliber? Considering a Barrett 50 Cal is the most powerful "anti-material" (sniper) rifle designed to shoot through thick armour plating kinda makes a boltgun look like a really sophisticated bit of kit for a grunt to use!

And by the way, you have to be lying down to fire a Barrett 50 cal so games like CoD:MW are lying to you, no way you could fire one standing up because you'd be on the floor 10 feet behind you so to fire a 76 cal gun stood up, either the gun or the soulds would have to have great technology to counter the recoil.

To you sir I say, http://www.youtube.com/watch?v=joKVVdL81Io

You could see the weight of the rifle upsetting his balance greatly.

Then again,

http://www.youtube.com/watch?v=51CTM49rcrs

Lol just saying there aren't to many weapons that one CAN'T fire standing, he also isn't ten feet behind where he started. Given he could have meant an automatic 50 but those were never meant to be shot standing XD
The rifle weighs a ton man lol I found a ton of vids where guys shot it standing =) it's all about the person. Also, with boltguns you have a superhuman holding them with servo assisted armor. =)

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?)

im2randomghgh wrote:And there was brief mention of the speed in Savage Scars, Sarik estimated it moved at mach9 or so which, given the sensors in his helm, is likely accurate.

Or rather inaccurate, as Mach numbers are pretty useless as a measure of actual velocity.

The speed of sound varies quite heavily (very roughly, about half a m/s per degree C at normal-ish temperatures). As such, a velocity of 3200 m/s would be roughly Mach 9 if it were 40 Celsius, but Mach 10 if it were -20 Celsius.
On Earth alone, Mach 9 could cover a range of actual velocities over 800 m/s between high and low. Take into account the different atmospheric composition (which also changes air density) on other planets, that widens even further.

In truth, there are very few contexts in which Mach numbers can be used as a serious measure of velocity where the speaker should not be then be subsequently slapped one for doing so. Fluid flow over an aircraft's fuselage is such a subject. The detonation mechanics of an explosive is another. Projectile velocity is most certainly not.

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.

Connor MacLeod wrote:If your'e being technical yes mach can vary becuase speed of sound is material dependent (in water its 1.5 km/s)

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.

im2randomghgh wrote:

iproxtaco wrote:That's a joke post, right im2randomhghg? I don't think I've ever seen someone straw man another poster quite as badly as that. Even then, I don't think I've ever seen anyone be so condescending and arrogant at the same time.

The driving part was a joke.

The rest wasn't. Giving nations cart-blanche to do whatever the hell the want during wartime is a ridiculous idea. Not all the examples are temporary and small in scale like the flame-thrower: being aloud to drop nukes and anthrax at will would have much, much longer lasting effects.

Which is why I think you're straw-maning the argument.

Grey Templar isn't arguing, and neither am I for that matter, that things like chemical weapons and flamethrowers are OK to use. He's saying that war is war, people will die regardless of the method. Having a bunch of basically unenforceable international laws is relatively pointless unless it concerns a nation where the consequences actually matter, like the UK and US, who both have pretty strong stances on these kinds of things, will face the fallout from their citizenship and other western countries. However, if the government of a country rules without that, the laws don't mean anything, and thus the only way to enforce them is easily corruptible and potentially causes more harm that it's worth.

Look, my comments on the Geneva Convention seem to have derailed this.

Our personal agreements or disagreements with international laws are not at all relevant to the subject at hand - the only relevance those laws have to the actual discussion is that the weapons used by our armed forces are potentially not as formidable as they could be where they not thus restricted.

With that in mind, kindly keep your opinions on how pleasant you think our mutual murder of each other should be to yourselves.

To settle the railgun argument it actually says in the lore that the railgun punched a hole through a Leman Russ, which means it could not demolish a building.


Automatically Appended Next Post:

redkommando wrote:I honestly thought the Bolter would be more like this:
http://en.wikipedia.org/wiki/Anzio_Sniper_Rifle_20mm

The boltgun has more power, alot more.

Well a tank is built quite differently from a building.

A railgun could certaintly bring down a building, eventually. If it was aimed at structural supports and stuff. But yeah, the chance of a single railgun shot(not submunitions) taking down a building is quite slim.

Okay, let's nail this. The Geneva Convention exists as a means of protecting those who are not, or are no longer, taking part in the hostilities. This means civilians, wounded soldiers, non-combatants (such as medical staff) & Prisoners of War. It defines areas such as interrogation (name, rank, number), treatment of PoWs & civilians, allowing non-combatant staff to do their job (religious & medical staff basically) and even be paid for it - interestingly it states that medical staff should not be detained under any circumstance so that they may continue to do their work.

When you're talking about prohibited weapons you're talking about the Hague Conventions, notably the 1929 one which centred around biological & chemical weapons.

Interesting, although i'm not finding a Hague convention in 1929.

I find a 1899 and a 1907 convention.

Oddly enough gas was outlawed before WW1.


Still a rediclous set of proposals with no way to enforce it, and hence is useless.

and there are no addendums preventing the use of atomic weapons.

butteredtoast wrote:

redkommando wrote:I honestly thought the Bolter would be more like this:http://en.wikipedia.org/wiki/Anzio_Sniper_Rifle_20mm

The boltgun has more power, alot more.

No, I wouldn't agree. Bolter rounds are shown as being very squat and thus a lot less massive than the 20x102mm bullet - my personal estimate puts them, at least after the expenditure of propellant, at about 50 grams (about half). The 20mm is also packing one hell of a velocity at over 1,000 m/s. A bolt, after burn, might roughly match that, but I'd also guess less again.

With the 20mm round likely having a similar or greater velocity to a bolt, as well as being considerably more massive (i.e. more kinetic energy and more explosive), I'd say that the bolter would fall short of the AP-HE variants of 20mm Vulcan ammunition.

But 20mm Vulcan is VERY nasty, so that's far from saying bolters are pansies.

@Sparks_Havelock: Whoops. But still - NOT the topic of conversation.

Yeah, the Bolter would still be very nasty for a submachine gun.

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.)

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.

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

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

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.