Continuing ... 40K Armor and Weaponry Levels

[Nabterayl]

Lasguns burn right through 1ft concrete slab, dude. Our 5.56 and 7.62 does not do that.
Can you source that for me? 40K, Necromunda, Inquisitor, Dark Heresy, and Rogue Trader all place the autogun and the lasgun at equal effectiveness against both naked flesh and armor. We know from our Guard sources that squad support weapons are of .30 caliber (c.f. the Ghost series, and the fact that "heavy" stubbers are of .50 caliber), which places autoguns at .30 caliber or less. Which means that a lasgun is of equivalent effectiveness of a .30 caliber or smaller combat rifle. It's almost certainly not of equivalent effectiveness even of a .30 caliber battle rifle, given the effective ranges that are listed in every source we have that lists ranges in meters.


That's impressive without a targeting computer--- I am sure it can fire farther--- but what's the point if you cannot hit a target?
Imperial fighting vehicles do have targeting computers. There's a big difference between not having artificial intelligence and not having computers. For instance, one of the things that makes the Leman Russ the tank of choice in the Imperium is precisely the fact that it does have a targeting computer, whereas many equivalent heavy tank designs do not (c.f. Honour Guard).


Uh... toughest weapons on the Leman Russ is NOT the sponsons gun--- it is the GIANT CANNON on the Turret.
I said the toughest "tank" in the Imperium. That's the Land Raider, at least from the perspective of an Imperial citizen. The Leman Russ is somewhat more sensibly designed, though it would still get a tank designer fired all the way back in like, 1945.


I have already explained--- what makes the Abrams cannon deadly is that it brings a building down on people, not the direct fire into a blob of people. If you fired the Abrams cannon at space marines, you'd probably maim one.
That might be true, sure. But remember that you can take a space marine out of action with a mere autocannon (c.f. the Dark Angels action on Taros against Missile Silo Decima), which doesn't have anything like the range, mass, or muzzle velocity of an Abrams' main gun. And you certainly can't use a battle cannon to put an enemy tank out of action that is so far away you can barely see it due to the curvature of the planet, or put an enemy tank out of action by shooting it through a sand dune (or at least I think it's uncontroversial that a battle cannon can't do that ... do you disagree?).

[Sorchus]

You are making a lot of assumptions about various 40k weapons that do not follow from what we know, first that caliber is the most important thing in determining damage. You make the leap that a 30cal machine gun is equal to one from our time when in fact we cannot because we do not know how much better the propenent is than our modern weapons.

One the absolute strength of the Leman Russ Armor, in a thread similar to this one over HERE (http://bbs.stardestroyer.net/viewtopic.php?t=109441) some people ran the calculations for the events from Honor Guard to determine Leman Russ armor. Look to the second page for the actual math. Needless to say the Leman Russ is highly resistant to armor penetration. As a high end estimate the Leman Russ is resistant to 12 inch Naval gun fire.

What do you base your belief that an Autocannon is not equal to a modern 120mm smoothbore Tankgun?

Note: I did not read over the whole prior thread, and this is my first post here.

[Nabterayl]

You are making a lot of assumptions about various 40k weapons that do not follow from what we know, first that caliber is the most important thing in determining damage. You make the leap that a 30cal machine gun is equal to one from our time when in fact we cannot because we do not know how much better the propenent is than our modern weapons.
True, but see below.


One the absolute strength of the Leman Russ Armor, in a thread similar to this one over HERE (http://bbs.stardestroyer.net/viewtopic.php?t=109441) some people ran the calculations for the events from Honor Guard to determine Leman Russ armor. Look to the second page for the actual math. Needless to say the Leman Russ is highly resistant to armor penetration. As a high end estimate the Leman Russ is resistant to 12 inch Naval gun fire.
Yes, but on the low end estimate a Leman Russ wouldn't stand up to a 1945 tank destroyer firing HVAP. The low end estimate is arrived at by assuming that plasteel is an amazing material and plugging in that assumption to our provided technical specs. The high end estimate is arrived at by assuming that Dan Abnett knows what he's talking about when he has tanks being thrown around by enemy fire. Since this is the same Dan Abnett who regularly has human bodies flung through the air by lasgun fire and who explicitly describes lasguns as firing laser beams, yet gives them shoulder-bruising recoil, I'm inclined to call the first methodology more reliable.


What do you base your belief that an Autocannon is not equal to a modern 120mm smoothbore Tankgun?
Two things. First is the depiction of autocannons in the sources. The classic 48" S7 AP4 heavy 2 autocannon is a man-portable weapon with a fairly high rate of fire, which would be impractical with 120mm rounds for reasons of both bulk and weight. In fact, I've never seen an autocannon described like a large-bore tank weapon - the name "autocannon" always seems to denote either a Bushmaster-type weapon or a medium machine gun-type weapon. As I understand it, the Rogue Trader-era phrase is "similar in concept to twentieth century tank guns," which is (i) not clearly inconsistent with depicting autocannons as light cannon, and (ii) superseded by newer fluff in any case.

And then there's this quote from Imperial Armour II:


The Land Raider's armour plating represents the very peak of the Adeptus Mechanicus knowledge and similar techniques are utilised on other vehicles, such as the main armour plating on Titans. The STC design means locally available materials can be used to replace the advanced alloys, but all Space Marine Chapter forges are capable of manufacturing the materials needed to produce Land Raiders.

The inner armoured layer and structural supports are constructed of adamantium. Above this is a titanium/plasteel composite rolled plate. This is used to reinforce the locations on the vehicle that are most exposed to enemy fire, such as the assault ram, front glacis, outer hatch doors and hull side. Next is a thermo-plas fibre mesh followed by the first of two ceramite layers. The first is designed for energy absorption and dissipation, an effective defense against high energy laser weaponry. The second is an ablative layer, the vehicle's first line of defences against extreme heat and melta weapons. The construction of this composite armour involves bonding the layers in huge high pressure cookers, where extreme heat and pressure are applied to the various layers to form the complete whole. The front armour is 98mm thick, but provides protection equivalent to approximately 300mm of conventional steel.

In the previous thread, Tynskel proposed that by "conventional steel" the author means "plasteel." Taking the two paragraphs in context (in particular noting that the author clearly knows and uses the word plasteel and that the entire book takes a "serious wargamer" approach to the 40K universe), I think that's a tortured reading - I think that "conventional steel" in this context means RHA.

If that is true - if a Land Raider's best armor has an RHAe of ~300mm - then we can start to get somewhere in comparing 40K weapons to historical ones. We would know that no non-superheavy vehicle (and possibly no vehicle, period, depending on how you read the Land Raider fluff) in the Imperium has a better RHAe than ~300mm. From that, we can infer weapon strengths in a general manner. We would know that whatever an autocannon is, it can't defeat ~300mm RHAe (which would argue for the light cannon interpretation, in my view - or at least would make the autocannon equivalent to an early war tank cannon, many of which themselves fit the light cannon interpretation). We would know that a krak missile and a battle cannon can only barely defeat ~300mm RHAe, under optimal conditions. We would know that even a lascannon is given very serious pause by ~300mm RHAe. And so on.

All of which would paint a general picture that the weapons we see in 40K are roughly equivalent in power to those used by developed nations circa the interwar period through World War II. Which pretty much fits the milieu in my opinion - certainly visually we're in that period of about 1920-1945, and many of the other vehicular specifications belong to that period as well. It is also consistent with the theme of technological barbarism.

And that is why I conclude that a .30 cal machine gun in 40K would be roughly equivalent in lethality* to a .30 cal machine gun of the middle 20th century.

* I say lethality advisedly, because 40K is certainly more advanced than the 1920-1945 period in other ways. For instance, as the StarDestroyer guys correctly point out, plasteel is really, really light (even if their KE and HEAT resistance assumption of 1.23 turns out to be a little high), and that lightness flows through to most of their war materiel. For instance, a man-portable autocannon weighs about 44kg unloaded, which is incredibly good if indeed an autocannon is a ~30mm rapid-firing light cannon. Guard flak armor is also incredibly light for the protection it offers, and of course the starships are so ridiculously light (a Lunar class cruiser has an average density of ~0.00875g/cm^3) one suspects nobody has actually run the math. So there are ways in which 40K tech is significantly more advanced than that of 1920-1945; it's just that lethality generally isn't one of them.

[Connjurus]

It's the whole left-hand/right-hand thing, man. If the armor in 40k truly was that weak, then a freaking bolter would just rip through everything, as a bolter fires a .75c round with a mass-reactant detonating cap, a depleted uranium core, and a diamantine tip. Taking that into account, to say that lethality in the 40k universe is downgraded is just an ignorant statement. When you look at something that, in your words, is not "hard" science fiction, the fluff and the way things interact overrule most other things. When you consider that, you have to put the physics manual. You just have to. Because if the lethality of the weapons of the Imperium of Man is downgraded, that means that everything else is as well. Rail Guns? Pfah. Plasma? Nothing! Fire? Thanks for melting my marshmallows. Y'see? If a Lascannon has a tough time penetrating Land Raider armor, it's not because the Lascannon is weak - it clearly isn't. It's because the Land Raider's armor is tough. You have to compare this one source that you're getting to all the examples of Land Raiders taking punishment that an Abrahms never could. The Imperium of Mankind just couldn't survive in such a hostile galaxy if one of its most powerful tanks was going around in tissue-paper armor. You have to accept that the rest of the Galaxy, from the Necrons to the Daemons of Warp, don't just all decide to play nice and put away the mean guns when they play with the Imperium because the Imperium is the special kid on the block.

Sorry for the wall of text. :P

[Bean]

Nabterayal's really got you guys on this one. He's done his research. His comparisons are sound. The objections I've seen, both in this thread and others, are universally ridiculous.

His conclusion, though, is probably the wrong one to take from this exercise. Rather than presuming that an Abrams would ruin just about any 40k tank from much farther away than any 40k tank could fire (which is absolutely true, based on the information we do have about 40k technology) we should just realize that the people who tell us what 40k technology is share only one thing in common: they have absolutely no idea what they're talking about.

GW writers have failed to describe anything resembling a coherent or sensible set of battlefield technologies. Their descriptions do little more than illustrate how very little they actually know about the engineering of weapons and armor. Even worse, this same lack of knowledge has been expressed several times, in several different ways, by several different people over the course of GW's history.

The lesson to learn, here, is not to take 40k technology seriously at all. It was not written to be taken seriously, and it was not written by people who knew enough about what they were writing to warrant taking them seriously. Serious comparison to actual military technology really only serves to illustrate GW's failures in this area. It does little to provide a meaningful comparison between 40k tanks and real ones.

[Sorchus]

Yes, but on the low end estimate a Leman Russ wouldn't stand up to a 1945 tank destroyer firing HVAP. The low end estimate is arrived at by assuming that plasteel is an amazing material and plugging in that assumption to our provided technical specs. The high end estimate is arrived at by assuming that Dan Abnett knows what he's talking about when he has tanks being thrown around by enemy fire. Since this is the same Dan Abnett who regularly has human bodies flung through the air by lasgun fire and who explicitly describes lasguns as firing laser beams, yet gives them shoulder-bruising recoil, I'm inclined to call the first methodology more reliable.
The only lasgun that was described in Abbnets work as shoulder bruising has Larkins Long-lasgun that utilized hotshot ammo. That is nearly the most powerful Infantry weapon in the Imperium, and can have recoil just based upon the act of cooling the weapon. You are going to have to have a better reason than that to through out the entirety of the event than nitpicking a completely different event. So it should still stand as a high end estimate.


Two things. First is the depiction of autocannons in the sources. The classic 48" S7 AP4 heavy 2 autocannon is a man-portable weapon with a fairly high rate of fire, which would be impractical with 120mm rounds for reasons of both bulk and weight. In fact, I've never seen an autocannon described like a large-bore tank weapon - the name "autocannon" always seems to denote either a Bushmaster-type weapon or a medium machine gun-type weapon. As I understand it, the Rogue Trader-era phrase is "similar in concept to twentieth century tank guns," which is (i) not clearly inconsistent with depicting autocannons as light cannon, and (ii) superseded by newer fluff in any case.
The only place that (I know of at least) it is shown to be very close to a regular Tank gun is in Dawn of War, were it has a firing rate similar to a modern tank gun. Other things to note about autocannons in general is that it is a large Man portable weapon that closely resemble a light towed artillery piece (http://en.wikipedia.org/wiki/2.75_inch_Mountain_Gun). It is also never depicted as a fully automatic weapon (excepting the Hydra, also from Abbnets work). Even in the rules it's rate of fire is'nt that special or high.


And then there's this quote from Imperial Armour II:

Snipe IA2 quote.

In the previous thread, Tynskel proposed that by "conventional steel" the author means "plasteel." Taking the two paragraphs in context (in particular noting that the author clearly knows and uses the word plasteel and that the entire book takes a "serious wargamer" approach to the 40K universe), I think that's a tortured reading - I think that "conventional steel" in this context means RHA.
You think, but you have no evidence, whereas I can easiliy point to Necromunda to point out that what is considered a standard construction material by the Imperium easily out strips the capacity of modern steel and means that we cannot make the correlation between imperium conventional and RHA. Necromunda extends 10 miles into the sky (at it's tallest) and vastly out does anything we can currently comprehend in using as a building material.


All of which would paint a general picture that the weapons we see in 40K are roughly equivalent in power to those used by developed nations circa the interwar period through World War II. Which pretty much fits the milieu in my opinion - certainly visually we're in that period of about 1920-1945, and many of the other vehicular specifications belong to that period as well. It is also consistent with the theme of technological barbarism.

And that is why I conclude that a .30 cal machine gun in 40K would be roughly equivalent in lethality* to a .30 cal machine gun of the middle 20th century.

* I say lethality advisedly, because 40K is certainly more advanced than the 1920-1945 period in other ways. For instance, as the StarDestroyer guys correctly point out, plasteel is really, really light (even if their KE and HEAT resistance assumption of 1.23 turns out to be a little high), and that lightness flows through to most of their war materiel. For instance, a man-portable autocannon weighs about 44kg unloaded, which is incredibly good if indeed an autocannon is a ~30mm rapid-firing light cannon. Guard flak armor is also incredibly light for the protection it offers, and of course the starships are so ridiculously light (a Lunar class cruiser has an average density of ~0.00875g/cm^3) one suspects nobody has actually run the math. So there are ways in which 40K tech is significantly more advanced than that of 1920-1945; it's just that lethality generally isn't one of them. Your low-end estimate has no support besides the invalid supposition that 300mm conventional is the same as 300mm RHA, whereas we can be reasonable sure that the materials that Necromunda was created with have far greater strengths than that. Lowend presumption has no valid support, whereas the highend is based on momentum transfer calculations from one scene. Neither are conclusive yet only one actually stands on the basis of evidence.

Thus you still have yet to convince me as to the superiority of a M1 Abrams.

[Nabterayl]

we should just realize that the people who tell us what 40k technology is share only one thing in common: they have absolutely no idea what they're talking about.
Oh, to be sure. 40K's coherency is aesthetic, not rational. If you actually read the StarDestroyer thread that is essentially the takeaway.


The only place that (I know of at least) it is shown to be very close to a regular Tank gun is in Dawn of War, were it has a firing rate similar to a modern tank gun. Other things to note about autocannons in general is that it is a large Man portable weapon that closely resemble a light towed artillery piece (http://en.wikipedia.org/wiki/2.75_inch_Mountain_Gun). It is also never depicted as a fully automatic weapon (excepting the Hydra, also from Abbnets work). Even in the rules it's rate of fire is'nt that special or high.
Two shots a turn is quite high for a large-caliber cannon. That's the same rate of fire given to select-fire small arms at ranges where bursts are appropriate. c.f. Dark Heresy, where the autocannon's rate of fire is high, but below that of a heavy bolter.


You think, but you have no evidence, whereas I can easiliy point to Necromunda to point out that what is considered a standard construction material by the Imperium easily out strips the capacity of modern steel and means that we cannot make the correlation between imperium conventional and RHA. Necromunda extends 10 miles into the sky (at it's tallest) and vastly out does anything we can currently comprehend in using as a building material.
I'm not sure you're understanding my point. My point is not that "conventional steel" is the standard building material of the Imperium. Plainly it is not.

You've read IA2, right? It isn't written from an in-universe perspective. It's written from an out-of-universe perspective, describing the 41st millennium to a 20th-century reader. In this, the Imperial Armour series is almost unique among GW publications, and for that reason particularly valuable as a reference. If one were going to describe the armor effectiveness of a Land Raider to a 20th-century reader, one would not give a plasteel equivalence. One would give an RHA equivalence.

In addition, the author is plainly aware of plasteel, and makes a point of using the term. If he thought that "conventional steel" and "plasteel" were synonyms, why would he use both terms without ever making that explicit, in a technical discussion?

EDIT: This isn't a discussion about the superiority of an Abrams over a Leman Russ. We don't have enough data to really finish such a discussion. For instance, we have no idea what the effective range of a battle cannon is, and we don't know what is the RHAe vs. lasers, multi-meltas, and plasma cannons of an Abrams' armor. The question at present, I think, is simply what is the RHAe (apparently against all threat types) of a Land Raider's front armor.


It's the whole left-hand/right-hand thing, man. If the armor in 40k truly was that weak, then a freaking bolter would just rip through everything, as a bolter fires a .75c round with a mass-reactant detonating cap, a depleted uranium core, and a diamantine tip. Taking that into account, to say that lethality in the 40k universe is downgraded is just an ignorant statement. When you look at something that, in your words, is not "hard" science fiction, the fluff and the way things interact overrule most other things. When you consider that, you have to put the physics manual. You just have to. Because if the lethality of the weapons of the Imperium of Man is downgraded, that means that everything else is as well. Rail Guns? Pfah. Plasma? Nothing! Fire? Thanks for melting my marshmallows. Y'see? If a Lascannon has a tough time penetrating Land Raider armor, it's not because the Lascannon is weak - it clearly isn't. It's because the Land Raider's armor is tough. You have to compare this one source that you're getting to all the examples of Land Raiders taking punishment that an Abrahms never could. The Imperium of Mankind just couldn't survive in such a hostile galaxy if one of its most powerful tanks was going around in tissue-paper armor. You have to accept that the rest of the Galaxy, from the Necrons to the Daemons of Warp, don't just all decide to play nice and put away the mean guns when they play with the Imperium because the Imperium is the special kid on the block.

Sorry for the wall of text. :P
Just a quick quibble ... a bolter would not rip through armored vehicles if my reading is correct. A full-sized 20mm armor-piercing round, which a bolt shell plainly is not, can expect to penetrate what, about 30mm of RHA?

Look ... this is all for fun, right? If you're worried about my understanding of 40K in relation to itself I'd be happy to send you some fan fiction that I think will set your mind at ease. At the same time, I really think that 40K has more in common with BattleTech than with Star Wars, technology-wise. We all agree that 40K isn't internally consistent, right? I'm suggesting that one of the internal inconsistencies is that everybody's tech is pitched at a low lethality level (mind, just such "low lethality" weapons did a fine job making a hash of huge swaths of the world seventy years ago).

[eldargal]

Welcome to world of the historical warfare enthusiast, where everything is wrong because the people who write it don't know a damn thing.:) At least GW have an excuse, they started as a bunch of guys designing a roleplay/battle system based on what sounded good, rather than actual knowledge.

Personally, I just assume two things: 1) The actual game rules are allegorical and 2) there is a radical difference in quality of items in 40k. That Leman Russ which just got popped by an M1A1 Abrams found illegally parked in a lolng forgoten Admininstratum building on Terra is was produced on a world where the world alloy is slang for a prostitute. That other Leman Russ over there which just withstood a nuclear blast was produced on one of the prime Forgeworlds by techpriests who knew what they were doing and had all the most advanced techniques and materials at their disposal. Ditto for that lasgun whose discharge bounced off a mirror and slightl inconvenienced a passing rabbit and the one which burnt a whole through a Space Marine.

[Fellend]

Welcome to world of the historical warfare enthusiast, where everything is wrong because the people who write it don't know a damn thing.:) At least GW have an excuse, they started as a bunch of guys designing a roleplay/battle system based on what sounded good, rather than actual knowledge.

Personally, I just assume two things: 1) The actual game rules are allegorical and 2) there is a radical difference in quality of items in 40k. That Leman Russ which just got popped by an M1A1 Abrams found illegally parked in a lolng forgoten Admininstratum building on Terra is was produced on a world where the world alloy is slang for a prostitute. That other Leman Russ over there which just withstood a nuclear blast was produced on one of the prime Forgeworlds by techpriests who knew what they were doing and had all the most advanced techniques and materials at their disposal. Ditto for that lasgun whose discharge bounced off a mirror and slightl inconvenienced a passing rabbit and the one which burnt a whole through a Space Marine.

This made me laugh...alot, and now people are looking strangely at me.

[eldargal]

A pleasure to serve.:)


This made me laugh...alot, and now people are looking strangely at me.

[Gir]

Nabterayl, there is one major flaw with your arguments. You're basing some of it off game rules, which in their very nature, are abstract.

[Nabterayl]

Not the Land Raider argument, though. Fluff is pretty clear, I think, that an autocannon poses essentially no threat to a Land Raider, a krak missile or battle cannon poses only a very mild threat, and a lascannon only a mild to moderate threat.

[AirHorse]

I think its very clear what is intended tbh, if land raiders really did have armour that duff why would space marines even use them, power armour can practically take that kind of punishment anyway.

It is very obvious to me that everything in 40k was originally concocted without much thought of grounding it in reality, but as it established itself then they attempted to make things more believable by vaguely relating things to the present.

Sometimes it works fine and makes things alot cooler since they have the slightest hint of actually possibility(boltguns are a good example of this to me!). Sometimes they duff it totaly and make a mess of our understanding of what its supposed to be like.

[Lord_Crull]

In the previous thread, Tynskel proposed that by "conventional steel" the author means "plasteel." Taking the two paragraphs in context (in particular noting that the author clearly knows and uses the word plasteel and that the entire book takes a "serious wargamer" approach to the 40K universe), I think that's a tortured reading - I think that "conventional steel" in this context means RHA.
[/size]

The definition of conventional steel today is different from what it was say in the 16th Century. Besides, we have a least one example in Honor Guard of a tank taking a hit that would destroy a modern tank.



That might be true, sure. But remember that you can take a space marine out of action with a mere autocannon (c.f. the Dark Angels action on Taros against Missile Silo Decima), which doesn't have anything like the range, mass, or muzzle velocity of an Abrams' main gun.

An Iron Snake is shot point blank with an autocannon in Brothers of the Snake and he survives just fine.



You've read IA2, right? It isn't written from an in-universe perspective. It's written from an out-of-universe perspective, describing the 41st millennium to a 20th-century reader. In this, the Imperial Armour series is almost unique among GW publications, and for that reason particularly valuable as a reference. If one were going to describe the armor effectiveness of a Land Raider to a 20th-century reader, one would not give a plasteel equivalence. One would give an RHA equivalence.


I have to disagree with you there. I always got the impression that the Imperial Armor series was in universe.



In addition, the author is plainly aware of plasteel, and makes a point of using the term. If he thought that "conventional steel" and "plasteel" were synonyms, why would he use both terms without ever making that explicit, in a technical discussion?


For those in-universe who don't quite understand technology. Which I would imagine there are quite alot.

[Nabterayl]

The definition of conventional steel today is different from what it was say in the 16th Century. Besides, we have a least one example in Honor Guard of a tank taking a hit that would destroy a modern tank.
I like Dan Abnett as an author, and I like him even more as a Black Library author, but as a source, I think he's weak on the force with which things hit. Things get flung around in Abnett combat, whether or not it makes sense for them to be so flung. A 105mm shell moves a 62-ton "several meters" sideways. An unaugmented human woman kicks an adult male so hard he shatters a window made of "glascite" on a world with a toxic atmosphere. The "sheer force" of a laspistol drives back a man wearing power armor with "the bulk and proportions of a Space Marine." All these things happen when Abnett writes action scenes. I value Abnett as a source for lots of things about the universe, but the force with which things hit is not one of them.

Are we to start calculating the energy a laser bolt would need to move several hundred kilograms of armored individual on the basis of the fact that it happened in Malleus? Or do we seek some other explanation for these data? Abnett's force anecdotes can be satisfactorily accounted for, I think, by (i) the fact that Abnett uses force anecdotes as a stylistic device to emphasize the brutality of combat, (ii) the fact that Abnett generally choreographs his action with a cinematic sensibility, and (iii) the lengths to which his force anecdotes force us to go (e.g., if laspistols can stagger power armor, then how are combatants not knocked down or flung through the air not just when dramatically appropriate but every single time anybody is hit by anything; how does an unarmored woman kick a professional miner through any window, let alone one that forms a barrier against a toxic atmosphere?).

I don't have any such historiographically satisfactory account for IA2, and so far the best anybody has offered is that an author who used the term "plasteel" once decided to equate it with "conventional steel" five sentences later without notice. In fact, I'm especially skeptical because the Land Raider entry is not the only time the IA2 author uses the terms "plasteel" and "conventional steel." Consider the following:

According to IA1, the Leman Russ is made of "a reinforced cast plasteel hull and turret, strong enough to withstand the impact of most enemy shells and weapons." This gives us a warrant for concluding that the Leman Russ' armor is plasteel, as was noted in the previous thread. As IA1 says, the thickest armor on a Leman Russ is 200mm thick. So we have Leman Russes with 200mm of plasteel armor on their front turret glacis.
According to IA2, a Predator's inner layer of armor is "a bonded ceramite/adamantium alloy which provides protection equal to over five times the same width of conventional steel, whilst being lighter." The second layer is "a reinforcing thermoplas with a sub-dermal energy dissipation fibre mesh" and the other layer is "a non-magnetic acrylic identification sheath." All three layers "correspond[] to over 200mm of conventional steel on the front of the vehicle." A Predator's listed front armor is 65mm.

Again, we have the use of "conventional steel" by an author who plainly is not afraid to say that armor is made of plasteel. Moreover, if "conventional steel" means "plasteel" to the author of IA1 and IA2, then a Predator's front armor is equal to that of a Leman Russ. Isn't that contra-fluff?


An Iron Snake is shot point blank with an autocannon in Brothers of the Snake and he survives just fine.
Out of curiosity, what kind of autocannon? A Ghost-type autocannon? Or an everybody-else-type autocannon? Either way, this is yet another example of an autocannon that is no heavier than a light cannon, isn't it? I have a hard time imagining armor that can be defeated by bolt fire standing up to supersonic 120mm rounds.


I have to disagree with you there. I always got the impression that the Imperial Armor series was in universe.
IA3, 5, 6, 7, and 8 are mostly written from the perspective of somebody writing history, with a very occasional lapse into showing things from the xenos perspective. IA4 is written from the perspective of somebody writing history with a lot of primary source material thrown in.

IA1 and IA2 are different; they speak as if the 41st millennium is the present, but they speak as if they are outside of the 40K universe itself. For instance, the following excerpt from IA1 assumes that the reader has a greater understanding of the nature of technology than does the Adeptus Mechanicus:


In the 41st Millennium, technology is not widely understood .... Technology, lost in the depths of time, which is re-discovered is revered in a manner more akin to a religious artefact than a simple electric generator or fuel pump. Knowledge has become so debased that advanced systems are more comparable to witchcraft or magic. Working machines are always treated with reverence, it has a will or soul of its own, or as a manifestation of the Machine God.

The "speaker" of IA1 and IA2, moreover, clearly has knowledge that nobody in the 40K universe has. To give one example, IA1 tells us that what the Adeptus Mechanicus thinks are STC designs are in many cases not:


Many features that were originally modifications have now been accepted as STC and duplicated as such. In this way, what the Techno-Magi currently think of as pure STC designs are not, but lost in the mists of time. It is now impossible to separate original from adaptation.

To give another example, IA2 tells us facts about the Dark Age of Technology, which no 40K historian would know:


The Predator first saw service during the Dark Age of Technology, when it was the standard battle tank of all Mankind's fighting forces. It was first built as a response to a newly encountered threat from a violent and warlike alien race - the Orks ...

For these reasons, I maintain that IA1 and IA2 are written from an out-of-universe perspective, to a 20th century reader in the historical wargamer tradition. Which still makes rolled homogenous armor the best candidate for "conventional steel," I think.

[Old_Paladin]

One thing that keeps coming up in this discussion is the the autocannon, or 'autocannon' *air quotes*

It clearly a general term for a very wide family of weapons; with the exception of calling stubbers autocannons.
It clearly ranges in caliber and 'in world' effects, but all cause a similar 'in game' effect.


One thing is that we know they cannot be as small as a 25mm weapon. The heavybolter is 25mm with an explosive head. So it has to pack more punch then that.

So a light autocannon is probably at least a 37mm weapon (reaper, and other pre-heresy models) maybe even 50mm (dreadnaughts, towed weapons, hydra mount). Tank mounted ones are probably 75-88mm guns (and cause up to two hits from the chance of being hit from shrapnel).
In Ben Counters short story Defexio, the exterminator autocannons are a single-shot handloaded pair of heavyguns with massive recoil.

[Nabterayl]

So it has to pack more punch then that.
I think you're a little high in your estimates, but I agree with your autocannon analysis in principle. One thing I note is that an autocannon of 25mm could pack more punch than a heavy bolter of 25mm. Bolts are consistently depicted as being fairly short rounds, and a heavy bolter can be fired from the hip by an exceptionally strong human being (apparently it can even be fired on the move by a strong enough human being, judging by Harker).

We have no record of autocannon being fired that way (Bragg fires "autocannons" from the hip, but autocannons in the Ghost series are demonstrably smaller-caliber weapons than a heavy bolter). So a 25mm autocannon firing a longer round without rocket propulsion could pack more of a punch than a heavy bolter and still fit all of our data. I agree that some and possibly many autocannon are likely higher-caliber than that, but I don't think we need to assume that autocannon are higher-caliber than heavy bolters simply because they hit harder.

EDIT: That's hilarious about Counter, in that a hand-loaded autocannon is an oxymoron :p

[Old_Paladin]

I think you're a little high in your estimates, but I agree with your autocannon analysis in principle. One thing I note is that an autocannon of 25mm could pack more punch than a heavy bolter of 25mm. Bolts are consistently depicted as being fairly short rounds, and a heavy bolter can be fired from the hip by an exceptionally strong human being (apparently it can even be fired on the move by a strong enough human being, judging by Harker).

We have no record of autocannon being fired that way (Bragg fires "autocannons" from the hip, but autocannons in the Ghost series are demonstrably smaller-caliber weapons than a heavy bolter). So a 25mm autocannon firing a longer round without rocket propulsion could pack more of a punch than a heavy bolter and still fit all of our data. I agree that some and possibly many autocannon are likely higher-caliber than that, but I don't think we need to assume that autocannon are higher-caliber than heavy bolters simply because they hit harder.

I suppose a lighter caliber fired at much greater velocity could solve that problem (and even explain the range).

[Porty1119]

And Double Eagle included an Exterminator which was quite obviously armed with fully automatic autocannons :P
However, 'autocannon' has come to mean many things. I've heard anything from a 75mm recoiless rifle-esque autocannon to a light machine gun to a Bushmaster equivalent described as 'autocannons.' Another point, highlighted by the IA excerpt, is that not everybody in 40k uses the same 'STC'. Hence, the forge world-based variants. There is a reason why most Epic units look totally different from their full-scale counterparts. An Epic Thunderbolt is described as Bakka-pattern, and looks similar to the Forge World kit only in that it's a plane. If people need more examples, I'm sure I could dig more up.

[Nabterayl]

Along those lines, I note with interest that in the Guard codex, autocannons are described as firing "large calibre, high velocity shells at a prodigious rate" and in the Space Marine codex, autocannons are described as firing "large calibre, high velocity shells."

[RogueGarou]

A couple of points. Most tanks carry multiple loads for their main guns. The 40k abstraction for the game rules indicates that a tank carries one round for one weapon. There are a variety of rounds available for modern and older tanks on the real battlefield. I would posit that the Rheinmetal 120mm cannon on the Abrams would do more than maim a Marine in power armor depending on the shell type. The standard kinetic penetrator sabot round would most likely pierce the armor, penetrate the body inside, and exit the other side of thearmor quite handily. As the very high velocity penetrator moved through the target, especially in this case, an EXTREME amount of hydrostatic damage would be inflicted on the unlucky Marine. Also, the high velocity and small space of the enclosed armor could create a suction effect to rip tissues toward the breaches in the armor and would most likely be lethal to the unfortunate chap in the armor, genetic engineering or no.

A type of round which could also be quite lethal would be the HESH round fired from the 165mm cannon formerly mounted on the M728 Combat Engineer's Vehicle. This type of round fired what was essentially a large payload of plastic explosives which would deform to cover a large area of a surface and detonate quickly after this deformation. The result was a large area explosive shockwave which would cause structural failure in the target surface and would create dangerous shockwaves on the other side of the target, usually a wall. Creating violent shockwaves inside the body of a Marine would likely be very bad.

HEAT rounds might prove to be less effective since power armor is said to be highly resistant to extreme temperatures. However, if a HEAT round did burn/melt through the ceramite armor, it would probably be instantly fatal a Marine as the body inside the armor could not withstand the extraordinary temperature of the jet of explosive gases created by the warhead. Other types of round, such as canister/shot/grapeshot/whatever-else-it-may-be-called would likely be less effective due to the toughness of the power armor.

At different times I seem to recall stubbers and autocannons being listed as having varying calibers. This could be expected as different manufacturers and worlds would likely have different designs. There are numerous rounds currently and previously fielded which would fall into a general range of .30 caliber. 7.62mm NATO, .30-06, .30-30, .303, 7.62mmS, 7.62x54mm, 7.62x39mm, et cetera. Most anything in the 7mm or 0.3 inch area would be a .30 caliber round. These could be low velocity rounds fired from a short barreled pistol to very heavy rounds fired from rifles, machine guns, or lighter assault weapons. The performance of a stubber or autocannon will probably vary in the fluff but will be in a generic range to provide a middle ground abstraction of the weapon for the table top. I also recall seeing 20mm listed as the caliber for an autocannon, I think in one of the Gaunt novels.

Also, similar to the much larger cannon mounted onto a fighting vehicle, these smaller rounds can have different performances depending on the type of round being used. This is also not taken into much consideration for the table top to make things must faster and fun instead of sitting around and debating whether your Guardsmen would have been using a much longer barrel on their stubber with higher muzzle velocity and lower drag bullets which are actually a discarding sabot, light armor-piercing round instead of using the metal jacketed lead you thought they would use against your buddy's Orks.

It is absolutely correct that lasguns and autoguns are said to be roughly equivalent to each other. I do not recall seeing in any fluff or descriptions a lasgun burning through a foot of concrete, ferro-crete or other construction material. There are differences in the weapons but since most atmospherics do not come into play in 40k, they do not affect the weapons. One big difference was in the Necromunda reliability tests for lasguns versus autoguns. The idea was that a lasgun malfunction would be much safer and less likely than an autogun jamming or misfiring.

The ranges used in the game are not properly scaled. For instance, a model is roughly an inch tall. At one point in older rules, a level or floor was described as being three inches of movement, about three inches tall. Let's say the average person in the game is 6 feet tall that would put a level at about 18 feet which would be a really tall story or level of a typical building. A weapon snap-firing a couple of shots, represented by Rapid Fire short range would mean a soldier was snap firing a couple of shots at ranges up to 72 feet. It would also mean they were taking pistol shots at this range. Single aimed shots would be at 144 feet and be the extent of the rifles effective range. Fairly short for most weapons. Also, a standard table is around 4 feet by 6 feet which would put it at around 288 feet across. A battle cannon would have a range of 432 feet. Last time I checked, that would be pitifully short range for a main battle tank. It is an abstraction to make the game move smoothly and quickly. If I wanted to make a lot more calculations, I would go back to playing Micro Armor. :)

It was also pointed out that the design of tanks in 40k is pretty sub-standard. I absolutely agree with this. The shape of a Leman Russ would make it very susceptible to anti-tank fire, especially to the front and aide with all of those big, flat, perpendicular to the ground faces. A Land Raider or Rhino/Predator chasis would fare little better on side shots for the same reason. The turret on a Leman Russ is also quite small compared to modern day tanks and I would imagine the turret could barely hold just the breach for the cannon much less a gunner, commander and loader position. Sponsons and multiple turrets have been out of fashion in tank design for a very long time, as well. I am willing to suspend my disbelief for the sake of having a fun game and decent, fun-looking models, though.

Most games take some liberties with reality and abstraction to make the game work the way the designers want. Battletech was a favorite game of mine when it was still played in this area and I do miss it but it, too, had a lot of abstractions and suspension of disbelief involved. I like these kind of discussions about scaling the game into something approximating real world numbers. I do have a couple of pet peeves about the 40k fluff and consistency/reality, though.

For instance, why are lasguns depicted as having substantial recoil in all of the Gaunt novels and a lot of other fluff? Larkin is said to have a permanent bruise from the impact of the stock of his longlas against his shoulder. Why are boltguns described as caseless but a lot of fluff depicts cases flying through the air, even back when the sculpts and art did not have ejection ports on the weapons. There is even a medal awarded to Marines which is made from a spent bolter case. There are things I miss from older versions of the game and I felt that the abstraction and generic feel of the game went way, way, waaaay too far when 3E came out. I felt so strongly about it that I only played it a handful of times and did not start playing regularly again until 4E released. I still would like to see movement rates come back into the statline or some additional mechanic besides Run so that Eldar, Dark Eldar, and Tyranids get an extra bump on movement over the slower, less nimble races. Oh, well, I don't see that happening and people would probably complain when Grots, Tau, and Squats/Demiurg had slower base movement than everyone else because of their short legs. :)

[mysterex]

I like these kind of discussions about scaling the game into something approximating real world numbers.

I'll take you up on that.

A while ago I tried to work out how long a game turn, and hence a typical game was in "real" time. I used how long it would take a human to run 12 times their height as a basis and despite adjustments kept coming back to a result that meant games were well under 2 minutes long making the future super lethal.

So much mayhem in so little time. Doesn't seem to blend well with their fiction though - I guess the stories wouldn't be that dramatic if most of the main players were dead within the first ten pages of action.

[Old_Paladin]

I'll take you up on that.

A while ago I tried to work out how long a game turn, and hence a typical game was in "real" time. I used how long it would take a human to run 12 times their height as a basis and despite adjustments kept coming back to a result that meant games were well under 2 minutes long making the future super lethal.

So much mayhem in so little time. Doesn't seem to blend well with their fiction though - I guess the stories wouldn't be that dramatic if most of the main players were dead within the first ten pages of action.

The problem is that everything scales differently.

For example; a Leman Russ battle tank takes 41 seconds to move that same distance (not counting any acceleration time, just it's maximum speed).
That still means that at best, you're probably looking at 10 minutes. But it is still very quick.

[Melissia]

Why are boltguns described as caselessSource?

Most recent references to boltguns do not describe them as caseless. Indeed, Dark Heresy makes references to spent Astartes shell casings being considered something of a cross between a holy relic and good luck charm.

[Nabterayl]

That still means that at best, you're probably looking at 10 minutes. But it is still very quick.
I could actually believe that. I mean, by the time a 40K game has started, most meaningful maneuvers have already taken place. A game of 40K pretty much only depicts the part of a battle where people are actually shooting intensely at each other at close quarters, which is typically a pretty small part of any engagement, right?

[Melissia]

Yeah, that's pretty much it. It also depicts, for example, the survivors of an Ork Horde who were charging an artillery position, the arty probably having been bombarding them the entire way there, but enough of them got there that the arty position has to defend themselves.

[Aldramelech]

One thing that keeps coming up in this discussion is the the autocannon, or 'autocannon' *air quotes*

It clearly a general term for a very wide family of weapons; with the exception of calling stubbers autocannons.
It clearly ranges in caliber and 'in world' effects, but all cause a similar 'in game' effect.


One thing is that we know they cannot be as small as a 25mm weapon. The heavybolter is 25mm with an explosive head. So it has to pack more punch then that.

So a light autocannon is probably at least a 37mm weapon (reaper, and other pre-heresy models) maybe even 50mm (dreadnaughts, towed weapons, hydra mount). Tank mounted ones are probably 75-88mm guns (and cause up to two hits from the chance of being hit from shrapnel).
In Ben Counters short story Defexio, the exterminator autocannons are a single-shot handloaded pair of heavyguns with massive recoil.

Look at the Apache's M230 chain gun vs The A10's GAU8 Avenger Cannon. Both are 30mm weapons but have very different effects. Weapon caliber is not the whole story, ammunition, barrel length and weight, firing method and fusing method and velocity all play a part.

Its all kinda moot though. This is Sci-Fi, with a huge emphasis on the Fi! lol

[Melissia]

And yet here we are.


Personally, I see the Avenger as closer to an assault cannon myself.

[Aldramelech]

And yet here we are.


Personally, I see the Avenger as closer to an assault cannon myself.

That wasn't my point.

The point I'm making is that the caliber of a weapon is not the whole story.

Another good example is the M203 and the Bofors AA gun. Two very different weapons, but still both 40mm.

Don't get too hung up on weapon calibers.

[Melissia]

And you missed my point entirely as well. "And yet, here we are" iwas more in reference to the "it's all moot" comment. The latter part was my own suggestion-- the GAU-8/A Avenger is closer to how an assault cannon is depicted. It has nothing to do with caliber so much as it does with the general depiction of the Assault Cannon compared to the facts about the GAU-8/A Avenger.

[Aldramelech]

Why isn't there a blow Mel a big kiss smiley on here?

I demand one immediately!

[Paul]

Here's the way I see it:

The quote from IA2 is in-universe. It's the only explanation. Parts of it are quotes from out of universe and parts of it are from in-universe. I choose to believe (it is an option) that this is an in-universe portion.

It seems to me that RHAe in conventional steel is indeed plasteel, for the sake of sanity.

If it WASN'T the case, either the ENTIRE GALAXY in 40k is completely inept (Tau's most powerful antitank weapon penetrates 300mm RHAe 33% of the time?) or completely impossible to understand, such as the 25mm Rocket-Propelled Grenades (heavy bolter) which are less lethal than a .50 cal, since a modern M2 can pierce 40k's "Armor 11" rating.

I know the Imperium backslides, but it is ridiculous to imagine that the Advancing, or High-Tech Races (Tau, Eldar, Necrons) have technology that barely rivals the weapons-systems used in the Second World War on Earth! It's mind-bogglingly stupid to draw that conclusion from one quote in one book.

[Nabterayl]

Is it as mind-boggling stupid as the Earthshaker cannon, which outranges most weapons in the Tau, eldar, and necron arsenals by a considerable margin, being listed with a maximum [possibly effective, possibly just maximum] range of 15 kilometers?

[Paul]

Is it as mind-boggling stupid as the Earthshaker cannon, which outranges most weapons in the Tau, eldar, and necron arsenals by a considerable margin, being listed with a maximum [possibly effective, possibly just maximum] range of 15 kilometers?

That is rather dumb, actually. It might have been a typo, or an author knowing nothing about anything. I'd throw up my hands at this and say "You're right, Cold War tanks could take landraiders, and therefore Tau Hammerheads, Eldar Fire-Prisms, meltabombs (easily), plasma blobs (more easily), deathstrike nukes, etc." After all, the T-80U is my hero... lol

Join the T-80U > 40K everything club! Population me and Nabterayl!

[Porty1119]

Joined :P