Hi all

I came across this video and I though I would share. I started watching the In Range videos based on the Forgotten Weapons videos by one of the presenters. I find them all fascinating and informative about how firearms actually work.

Anyway in this video they do some live firing of ww2 era 8mm-ish explosive rounds into ballistic gel. Snipers on both sides on the Eastern front were apparently using this stuff. Yerg...

The results are pretty catastrophic and might help visualise the potential effects of an even larger round with more space for payload. Definately something I hope never to have to deal with in real life!

https://youtu.be/AXaaybiRiYY

Explosive rounds are still around today. More commonly found in 50cal size, so closer to what bolters would fire.

https://en.wikipedia.org/wiki/Raufoss_Mk_211

Bolters are canonically 0.75-cal, which is very close to 20mm.

So, a good analogue might be a 20mm grenade launcher- the Neopup PAW-20 is probably the best extant example. Here's a video of one firing live (explosive) ammunition.

As you can see the recoil is substantial, but it's still manageable in slow semi-auto by a human user. Throw in secondary rocket propulsion to boost the effective velocity and it's pretty much a bolter.

Good points all. I just hadn't seen a video before of explosive rounds in a biological equivalent material.and thought it was interesting, if pretty horrifying.

Also Forgotten Weapons has done a neopup video as well

https://youtu.be/QHbqHx3TLBE

 catbarf wrote:
Bolters are canonically 0.75-cal, which is very close to 20mm.

Not all - Godwyn pattern are 0.75 while Phobos are 0.70 and Tigrus are 0.60

I'm pretty sure most of the smaller ones are not meant for power armor users, though, and are more special issue inquisitorial equipment. Regardless, the "standard" is .75 with heavy bolters being a "standard" of 1.00.

there was a big thread about this a while ago. I still stand by my opinion that you wouldnt be able to fit all the components to have a round that has a rocket propelled secondary charge, inertia armed, impact delay explosive charge, into a bolter cartridge, even if they are .75mm...

Certainly not with modern miniaturization technology. But 40k doesn't use that.

Welcome to science fiction/fantasy.

indeed, but seeing as they still essentially using ww2 issue tank, aircraft technology, I've just applied that same logic to the scenario.

 queen_annes_revenge wrote:
indeed, but seeing as they still essentially using ww2 issue tank, aircraft technology

I didn't know we had laserguns, hovertanks, and plasmaguns in ww2! What a distant era of lost technology that must have been.

An open cylinder bore 12 gauge is almost. 75 in bore diameter, and there are explosive 12 gauge slugs, so the whole idea that bolters fire red bull can sized rounds is bull gak. An open cylinder 10 gauge would be bigger but obviously doesn't have the same kind of selection of rounds.

Yeah nowhere near that big. Even heavy bolter shells are only just over an inch in width.

 Melissia wrote:

 queen_annes_revenge wrote:
indeed, but seeing as they still essentially using ww2 issue tank, aircraft technology

I didn't know we had laserguns, hovertanks, and plasmaguns in ww2! What a distant era of lost technology that must have been.

Yawn. why not maybe try adding something constructive to the converstaion?

 queen_annes_revenge wrote:
Yawn. why not maybe try adding something constructive to the converstaion?

You first, kiddo. 40k has always been about strange technological and tactical anachronisms, since the very start. Saying "this kind of thing is impossible IRL" is pointless, irrelevant garbage.

Even assuming that technology hasn't progressed in the setting since the Heresy one would think that weapon technology had advanced beyond current standards in 28000 years.

A rocket round would be longer though as the proportion of propellant in the casing is reduced to basically enough to.get it out of the barrel.with the rocket kicking in after that. Also I recall bolt rounds being mass reactive rather than impact armed, so.that would probably help with miniaturisation

 Melissia wrote:
Certainly not with modern miniaturization technology. But 40k doesn't use that.

Welcome to science fiction/fantasy.

I figure it's mostly a matter of finding an explosive that has enough yield. And since this is a world where fairly large ships can take off from 1 G planets without having to drop any sections, it's safe to say that they have found that explosive. (Perhaps promethium, whatever it's made of.)

Pretty much all of science fiction runs on some kind of unobtainium.

Bolt rounds are just flechette rounds that replace the inert flechette with a mini rpg. Certainly not something that we’ll see on an actual battlefield anytime soon but bolt rounds are a pretty minor suspension of disbelief compared to a lot of other stuff in 40k.

 queen_annes_revenge wrote:
indeed, but seeing as they still essentially using ww2 issue tank, aircraft technology, I've just applied that same logic to the scenario.

See, there's your problem right there.

Canonically they also have grenades the size of marbles and "planes" that happily fly into space.

Well the grenades on the space marine models look like Mills grenades to me, again, ww2 era tech.


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Prestor Jon wrote:
Bolt rounds are just flechette rounds that replace the inert flechette with a mini rpg. Certainly not something that we’ll see on an actual battlefield anytime soon but bolt rounds are a pretty minor suspension of disbelief compared to a lot of other stuff in 40k.

I have no problem suspending my disbelief, but it's so inconsistently applied too. For example, you'd need some kind of inertial arming for the mass reactive charge, similar to that used in weapon launched grenades, but the books have them exploding in peoples heads after being fired execution style and all other sorts of craziness. Its minor details, but as an explosive technician it's things I notice.

Gadzilla666 wrote:
An open cylinder bore 12 gauge is almost. 75 in bore diameter, and there are explosive 12 gauge slugs, so the whole idea that bolters fire red bull can sized rounds is bull gak. An open cylinder 10 gauge would be bigger but obviously doesn't have the same kind of selection of rounds.

Yeah this is possible right now. This video is a little dramatic, but it demonstrates the frag 12 round which is very close to a bolt round, although it uses the propellant to travel rather than an inbuilt rocket.

https://m.youtube.com/watch?v=WV379084djs

Back in some early 40k pics the bolts had really short cartridges, stubby little ones which makes sense to me as they are only used to push the round out.

One thing I think people really don't appreciate about advocating stupid sized bolts is that it makes the magazines TINY.

A 1 inch bolt stacked in alternating overlap (let's say 50% overlap), means that every 2 rounds equals a vertical distance of 1 inch. So 30 rounds is 15 inches long, which is a one and a half foot long magazine. That's ridiculous by itself. A 0.75 cal stack of 30 is still ~11.5 inches, which is almost a foot long. Now this is assuming that they stack this way.

Any bigger than this is going to make the magazine capacity small, or the magazine's stupidly long.


It's one of my cosplay pet peeves that people make stupidly oversized bolters with muzzle diameters so large the corresponding magazine could Only hold like 4 rounds....

Muzzle diameter isn't always, or even usually, indicative of the bore diameter in military grade weapons. They'll have thicker barrels for heat absorption, so the muzzle ends up flaring quite a bit.

 Veteran Sergeant wrote:
Muzzle diameter isn't always, or even usually, indicative of the bore diameter in military grade weapons. They'll have thicker barrels for heat absorption, so the muzzle ends up flaring quite a bit.

While that's true,. There's a difference between that and what people have done:

https://www.thingiverse.com/thing:2138894

https://designedby3d.com/shop/bolt-pistol-cosplay-prop-from-warhammer-40k/

https://www.etsy.com/listing/560692153/bolt-pistol-replica-warhammer-40k-prop

https://www.thisiswhyimbroke.com/space-marine-costume/

https://technabob.com/blog/2013/05/18/warhammer-40k-blood-angels-costume/

http://mytpb.com/cosplay-thursday-space-wolf/

And the heavy bolters are worse, with bean can sized bores on the muzzles.

There's no way you can justify such oversized bores with the way bolts work. Unless the bolter barrel stops inside the casing and that thing is just a flash suppressor, but I don't think so given how short the barrel already is...



I've got no problem with big and chunky guns for marines per se. IMO as they are heavily armoured they need armoured weapons. Especially as they carry their bolter across their chest. The kind of incoming fire they would get means they could easily lose function in their gun from shots aimed centre mass.

So my perception is that the bolter you see marines carrying is basically shrouded in an armoured case. It's the armour that makes it heavier, not being a 'marine' version (one of the few things I really hated in the ffg RPG). An imperial guard bolter would just remove the shroud, but it would still be the same gun.

 Flinty wrote:
A rocket round would be longer though as the proportion of propellant in the casing is reduced to basically enough to.get it out of the barrel.with the rocket kicking in after that. Also I recall bolt rounds being mass reactive rather than impact armed, so.that would probably help with miniaturisation

I basically assume that the casing on a boltgun round is actually the rocket motor and is pushed out attached to the "bullet" rather than burning in the chamber, since you only need a small boost charge to get the round out of the barrel. Picture:

Yeah, but there's a ton of other elements that would need to be present. a venturi for the rocket motor, some sort of spin stabilisation system (although this can be done using diagonally offset venturi to impart spin) plus, a rocket motor needs some length to actually burn down. a stubby little chunk of rocket propellant like that will just deflagrate in a burst of flame. And then on the actual projectile, you'd need a hardened penetrator to get through any armour (definitely not enough room for a shaped charge as well as all that) and some sort of delay PIBD initiation system for the explosive charge.

also, you've got to consider the practicality of having rocket propelled rounds. we already have propellant rounds that are more than capable of taking projectiles across huge distances. generally, the combat in 40k takes place in much closer range. rocket rounds are totally unnecessary.

It's not as crazy as it sounds. The gyrojet shot rocket-propelled rounds that were around .50 caliber. It had issues with accuracy and manufacturing the ammo was a headache, but it actually worked.

A bolt would simply be a bigger, much more sophisticated version of this. It's about as realistic as a lasgun power pack containing enough energy to shoot (a few dozen times) a laser powerful enough to kill someone...

In my humble opinion:
I think the bolter is a hybrid gyrojet/ballistic weapon that in human sized calibres is approximately 12-14mm and in astartes pattern(which is what I will continue to talk about) perhaps 20mm while the heavy bolter and perhaps bolt rifles of the primaris marines would be approximately 25mm(it is heavy afterall).

Although the bolt rifle maybe a 25mm necked down to 20mm. Velocity gained through traditional ballistics would be more suitable for close quarters penetration against armour, while the rocket would provide a much longer effective range against armoured foe (ie astartes). This would explain the extended range.

I think for it to work it would not look like it is displayed, this round is much too short and has no advantages from being so stubby. This would indicate this weapon is a glorified grenade launcher, and a poor one at that.

Basically a long projectile is stable (and has more room for rocket fuel and thus velocity) and more powder behind that means you have a higher velocity leaving the barrel of the weapon. So more AP up close.

A fat round is only good for explosive payload. At this point you want to look at their idea for penetrating armour, as this weapon seems to be designed (in my eyes at least) specifically for killing armoured astartes (penetrating their ceraminte power armour and blowing them apart and therefore bypassing their traditional hardiness). And I guess when you got a weapon designed to do that, well it works against most things.

The traditional fat blunt round is not promising here. Might be concealing a HEAT tip. Although not big enough for a tandem warhead(which depending on how their armour and black carapace works may actually be critical, it has occured their big bulky armour maybe a similar spaced armour shell as you see on the Challenger and Abrams). Although I read something about something depleted being put in the tip. Uranium I guess is their inspiration, and that is no shape for a kinetic penetrator.

At least this is what it wants to be.

Sadly very clearly it can not be such an effective weapon, because every guard unit has acsess to a lot of heavy bolters, and they seem to perform insignificantly greater than a M2 browning or have much more AP power than fragementation from a 40mm frag grenade. In other words it can puncture up to like 25-30mm of RHA which is pitiful. So basically it's a marine carried 14.5-15mm carbine, flying at pitiful speeds, skinned as something else more exotic.

Basically to be what it indicates it wants to be (by fluff description) it needs to ignore feel no pain saves (ie you might be a tough pipe hitter and all but I just blew your arms off,(or a melon sized hole in your torso(I'm talking big ass watermelon, none of those pussy honey dew or rock melon sorts here)) you are by definition combat ineffective) It needs to really hurt light vehicles. It needs to do 2 wounds and slaughter guard equivalents in the biggest case of over kill ever. In the hands of an astartes it should reach across the board with a range usually reserved for high velocity tank cannons and with a terrible accuracy.

The game rules are an abstraction. The bolter has more strength and better anti armour capability than a normal ballistic rifle (I.e. the autogun) this is an abstraction of the extra possibility of killing the target through a direct hit causing catastrophic internal damage, or from near misses triggering the mass reactive charge and peppering shrapnel into the target. Heavy bolters again have a step up in strength and AP based on higher rate of fire and larger projectiles, I.e. a burst of fire from a heavy bolter is more likely to be effective than one form an ordinary bolter.

One dice roll does not necessarily indicate a single round fired.

see you say that, but what does mass reactive even mean? most people seem to think it means that the secondary explosive charge will detonate after penetration into a significantly solid object, eg a space marine with his armour and huge bulk. this in itself would require some sort of detection system or device.

what you say seems to suggest some sort of proximity sensor, which would be even more complicated to get into a shell.

In 40k terms, "mass-reactive" merely means that it has a split-second fuse before it explodes so it explodes an instant after impact and penetration instead of on impact. The idea being it penetrates then explodes for maximum damage.

I remind you, though, that it still really doesn't matter how impossible it would be to do this with modern technology.

So, a time delay secondary charge, meaning that provided it had impacted on something, the secondary charge would detonate regardless of whether it had penetrated an object or not, so not 'really mass reactive?'

Welcome to today's seminar: "Dealing With Science Fiction Authors Talking About Subjects They Aren't Experts In".

With open bar.

I cant remember where I got it from, but to me mass reactive means that the warhead explodes if the shell gets close enough to any significant mass. This could be because the shell has buried itself into a target, or if it gets close enough to something else. Given that modern inertia sensors can be extremely small I can imagine magical future tech being small enough to fit easily in a small calibre round.

6ou dont need any time delay for such a thing, although it means that you can never do a ricochet shot without even more complicated electronics. However given the size of a bolter I can also see it doing an OICW style programming of every round in order to prime the mass reaction detonation system just at the right distance from the target.

Addendum... seems like I got the idea from 2nd ed wargear book

My mistake... the proximity detonation version is a different munitions, as of 3rd ed rulebook with metal storm frag shells.

I like how those illustrations make the bore seem even larger than on the models.

Again, if this were to be effective, I can't see a stubby little shell like that doing it. Rockets are sort of long for a reason, on second thought that looks more like a Carl-G (or similar recoil-less rifle) shell than a rocket. These image show clearly that the bolter has a propellant casing that are shown as seporate to the projectile so it is conventionally ballistic to a degree, if you are playing what you see is what you get lore wise.


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BTw i wonder what qualifies as a sudden increase in local area mass? If some Necron used a mcguffin to increase local gravity would marines find their ammo cooking off? If you dropped a live bolt round would it explode?


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But my point also continues, there is no reason to have a hybrid rocket/conventional ballistic weapon unless you are wanting to kill armoured foes at very long range. With great precision. This would actually be a more suitable use of space marines, because when you're in the middle of everything mixing it up you are not as effective(you have a smaller impact on a smaller part of the battlefield, and its much easier for the enemy to call a little something like a heavy artillery box barrage on you. Which would see you and any rescue efforts turned to scrap).


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Bolter shouldn't compare to conventional infantry weapons (at least an astartes bolter in my view anyway( yes i'd support the added complication of buffing all astrates weapons in strength to represent that they are beefed up weapons this would be a race wide buff so it would not be hard to implement (becasue why else would you beef up marines and pt them in power armour?)) I compare the bolter to the heavy stubber: m2 browning, browning 30cal, or forgeworld's MG42(even listed in lore of the war on Vracks as being an identical cartridge to the German WW2 8mm) and in comparison it is not great. It's an assault weapon you'd expect to put out the lead, but a bloody kelemorph puts out more lead with his revolvers. Hell in the right circumstances russ puts out more rounds with it's frikin howitzer(battle cannon). And well, that says a lot about the bolter's performance.

Gyrojets exist and they got up to mach 1. The burn lasted for a second or so according to the wiki, but that was a 13mm long 0.51 cal rocket.

https://en.m.wikipedia.org/wiki/Gyrojet

75 cal bolt rounds are bigger and and longer, giving it more burn time and room for the explosive


Couple that with the explosive round available for shotguns:

https://m.youtube.com/watch?v=WV379084djs

And you got bolt rounds.

The advantages (in being light and low recoil) a gyrojet offers are not really applicable to a a marine. Also it does not do the damage you'd want to if you were taking advantage of this style platform. A marine is a really big toughffin in power armour, it does not care about recoil or having a lighter weapon. A lighter weapon just makes a crappier club when you need to use it as one. A marine is engaging threats either far away(battlefield) or point blank (breaching in a ship ie living up to their actual name) a rocket proppelled projectile is unsuited to this later task. It would make more sense for it to be a hybrid.

I can't get over how ridiculous "depleted deuterium" is. Deuterium isn't an element, it's an isotope of hydrogen.

What does "depleted" even mean when you're talking about a given isotope? For uranium, "depleted" means the radioactive isotopes have been removed, leaving only the stable ones. For hydrogen, the radioactive isotopes are already ridiculously rare, why would you deplete it of anything?
And pure deuterium, in normal conditions, is a gas. How/why would you make the core of anything out of a gas? A gas with a density close to that of helium, too... I mean, if it's meant to act as an explosive, there are plenty of better ones. Deuterium is useful in some nuclear reactions, but I don't think anyone has ever claimed that bolters were miniature H-bombs, right?

Anyway, we know the writers at GW aren't scientists. It's really better to ignore the details or you'd spend all your time pointing how dumb everything is in 40k. Bolts work the way they're supposed to because it's cool and that's that.

And lasgun power is measured in megathules... I would tend to ignore the naming conventions to a certain extent

In terms of cooking ammo off, I imagine that the detonator.only.gets.primed when the round is fired. I guess you could try to.create.a localised gravity field.next to the bolter.muzzle, but if you are doing that then the bolt rounds aren't going to hit anything anyway regardless of whether they detonate or not.

A fin stablised missileette would also suit the name bolt. As it would look (at least a bit) like an actual crossbow bolt, which would make the inquisition's crossbow style bolters make at least a little sense.


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It would also be badass.

 Melissia wrote:
Welcome to today's seminar: "Dealing With Science Fiction Authors Talking About Subjects They Aren't Experts In".

With open bar.

I find it's best to shrug, cite Clark's Third law and not think too hard about things like this.

Alternatively I find it an interesting thought exercise to take the core parts of something and use logic to make it work and estimate it's power, measured against what we currently have and know about.
Although that might be because I write about stuff, and I hold that if I do not understand things I'm writing about (or don't make an effort to, or that it does not stand up to a short interrigation of logical thought) it's not worth writing about.


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Obviously it is better to make it work in the simplest way possible. This is my line of logic, you can pick it apart if you want.

Hence bolter has casings-> ballistic. Don't care what they say, evidence seen with my own eyes. is gyrojet as well-> hybrid ballistic and rocket-> Advantages over ballistic or rocket by themselves? Yes, a few disadvantages few in comparison to what it brings to the table.

Big calibre -> Explosive payload and explosive form of penetration? yes likely. -> big calibre kinetic penetration inefficient, excessive drag.

Gyrojets/rocket bullets unfortunately never went anywhere for a reason, and it's because they can't hit the broad side of a barn. When a bullet leaves the barrel, it's going as fast as it's gonna go already, and any environmental impact such as wind is going to have comparatively little time to act on the projectile. The Gyrojet isn't even lethal for some time out of the barrel, doesn't reach peak acceleration for a couple of meters, and then because it was so slow and everything has so much time to act on the projectile, that you can miss vehicle sized targets at a hundred meters.

The problem with hybrid concepts the way 40k often likes to portray bolters, with a classic primer ignited initial stage taken over by the rocket, is that it would still suffer from this problem (not a acutely, but still badly) and if you're already going with a conventional initial stage, why bother with the rocket second stage? It adds no value, just beef up the initial stage a bit, drop the rocket engine, and get more payload, better accuracy, and substantially less complexity. Unless the projectiles are going to be self guided, there's no purpose to an on board propulsion system.

To be fair, I doubt there's been a ton of R&D put into that kind of small rocket projectiles, while traditional firearms have existed for more than a thousand years. And the first ones were pretty awful too...

The advantages of the gyrojet were that the weapons were really light (since they were basically just a launch tube) and had very little recoil. So, in theory, you could make the projectiles be pretty big and heavy without having to worry about the user breaking their shoulder when firing. Going as far as "soda can bolts" is still dumb (because you want to be able to carry more than a dozen at a time), but that leaves room to shoot much more than a simple solid bullet.

Now since we're into sci-fi territory, the major advantage a rocket has over a bullet is the possibility to control its trajectory in flight: theoretically, you could have a smart projectile that compensates for both gravity and wind to have an almost perfectly straight trajectory. Space marine bolts don't seem to do that, though, so it's kind of a missed opportunity

They came up with the bolter originally because the writers wanted a really noisy terror weapon and it was the 1980s and bipropellant ammo sounded super awesome. This thing will go BANG RAAAAARK BOOM with every round. Effectiveness on the battlefield can be hand waved away with futuronium based materials and targetting/guidance technology.

Is it possible to make a bolter with modern technology? Definately. Would we want to? Not really as the modern military has no requirement for such a weapon. Too hard and expensive for too little additional effectiveness over standard bullets.

Yep, given the era, the future was "caseless" and "gyrojet", etc. etc. Typical madness in the 80's sci-fi world.

The reality is, from what we see in games and art, it's simply a 20-35mm sized carbine, with normal cases, firing a normal shell. They could easily fix this in the fluff and simply have innumerable versions, variants and patterns of bolt guns of course. Likewise, ammunition could vary. It's as simple as "During the Horus Heresy, caseless ammunition was difficult to produce and acquire, so manufactorums began designing a simpler cased cartridge, using bla bla bla...."

There are far greater sins of weapon design in the 40K universe/models/lore...you need only look so far as the gas operated(?) bolt action sniper rifle for the Necromunda fellas...where the bolt itself is captured inside the receiver and cannot be operated...etc.

 Vaktathi wrote:
Gyrojets/rocket bullets unfortunately never went anywhere for a reason, and it's because they can't hit the broad side of a barn. When a bullet leaves the barrel, it's going as fast as it's gonna go already, and any environmental impact such as wind is going to have comparatively little time to act on the projectile. The Gyrojet isn't even lethal for some time out of the barrel, doesn't reach peak acceleration for a couple of meters, and then because it was so slow and everything has so much time to act on the projectile, that you can miss vehicle sized targets at a hundred meters.

The problem with hybrid concepts the way 40k often likes to portray bolters, with a classic primer ignited initial stage taken over by the rocket, is that it would still suffer from this problem (not a acutely, but still badly) and if you're already going with a conventional initial stage, why bother with the rocket second stage? It adds no value, just beef up the initial stage a bit, drop the rocket engine, and get more payload, better accuracy, and substantially less complexity. Unless the projectiles are going to be self guided, there's no purpose to an on board propulsion system.

Unless you want to kill armoured enemies (astartes) at several kilometres. Also guided ammo would be badass. That was my interpretation of the reason to have a hybrid. But as the bolter is describd as an assault weapon suitable for close range engagments I'd have to agree to drop the rocket motor in this circumstance.

It could be argued it is to counter recoil in space, but the bulk of an armoured marine with mag-clamped boots on a firm surface. Well recoil is again looking like a non-issue.

Something to consider is the propellant could also be part of the explosive.

The closer the target, the more propellant remaining to add to the explosion.

If you have a high explosive bursting charge, any effects from additional left over rocket fuel are going to be pretty negligible.

Probably best mordern day equivalent would be a automatic cannon IMO.

25MM Cannon fired from the US Bradley is a good example.

Hellebore wrote:
Something to consider is the propellant could also be part of the explosive.

The closer the target, the more propellant remaining to add to the explosion.

Generally you want propellent to be a slower burning more constant push. Explosives you want as quick a burn as you can get. Not to say you can’t use different kinds for the same job, or what the properties space magic chemistry can produce. Unused propellent can definitely splash around and burn, but more as fallout then extra bang.

I'd love to see what the gw designers envisioned the working parts and operating system to be on those bolters more than the bolts themselves... I know there are some diagrams, but jeez... Is it gas operated? I cant see it being blowback or recoil.

its probably a combo of delayed blowback & gas

Given the size of the thing it could just be electrically operated.


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In fact the cutaway diagram of the storm bolter I posted above has a piezo-electric ignition chamber, and a blast vent directly above the chamber, which would suggest it is electrically fired with no real use for the waste gas. Ejection can be through either side and is selectable so even that could be electrically driven.

Might come in handy in the void, you'd want to shield it quite well to stop it getting EMPed. Should have a wind up lever on the side, for extended ops.

Or like, plug it into the plasma reactor on your back

 catbarf wrote:
Bolters are canonically 0.75-cal, which is very close to 20mm.

And have a 30 round magazine?

This coming at the time when the LRBT was determined to have a 120mm cannon - the barrel muzzle is significantly bigger than a Guardsman's whole head...

None of Matt Ward's scales make sense... The 'characteristics lore' introduced around that time tried to apply relativistic values to 40k to bring in an appeal to the military junkies...

LRBT would have a barrel closer to 203mm or 280mm...
A Bolter would have a magazine of 10-16 rounds - actually the old game, Fire Warrior made possibly the best representation of the Bolter seen... ever!
The individual bolts seem more reminiscent of a 2lb pompom at least in the old 3E lore...

Now quantify a real life equivalent using the 0.75" scale with the following:
Heavy Bolter
Autocannon
Battle Cannon
Earthshaker Cannon
Aquila Macro Cannon

And back on topic - the Bolt shells seem more akin to shaped charge projectiles - RPG's HEAT (High Explosive Anti-Tank) or HESH (High Explosive Squash-Head)

Looking up those and finding live-fire demonstrations brings out a plethora of articles ranging from the 1940's to now.

LRBT was just copied specifications of an M1 Abrams. But I wouldn't tank the model as being accurate. Not just because it's called 'heroic' scaling but because the model lack any kind of suspension, and of course the turret is too small to fit any kind of weapon breach. Let alone recoil systems. Unless it is armed with a water pipe and they convinced enough(captive I guess) orks it's a working cannon. That is what I'd do, and convince them it's a smooth ride.

I don't think a bolter would be 40mm. I know what you're saying with the firewarrior cut scene and the 2ib pom pom, but 40mm is getting to a realm where it should be combating enemies much more effectively than portrayed. If it's firing a HEAT warhead it should in that case be basically a krak grenade with 24' range and rapid fire.

I'd agree a HEAT round would be more suitable than the deterium capped impact fuse APHE shell that they seemed to push.

LOL I actually thought that those studs you sometimes see on marine armour was a type of ERA. It would also stop people hitting them with missile launchers from across the board...


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 Flinty wrote:
Or like, plug it into the plasma reactor on your back

Mowing down a heap of cultisits, plug comes out..."What's wrong Brother Gaius? Do you have a missfire?"
"God emperor damn them to hell! it's the vacuum cleaner situation all over again."

Teehee...

DakkadakkadakkadakkaBVVVVVvvvvvvvvvv....

Dang it!

There are modern sonars that can measure hardness. They used them to locate Hood and Bismark wrecks.It is not beyond the realm of possibility to use radio waves - or some other electromagnetic waves. And have the detonator set for just as density decreases. We have had radio proximity fuses since WW2. There could even be a delayed fuse backup - so many milliseconds after initial detection.

HEAT affects requires a broader warhead. There is a reason RPG7's have a bulbous warhead. HEAT has reduced effectiveness also when spinning - modern tanks have smoothbores for a reason.

The Deuterium tip is junk. Well they could use it as a filler so that the core doesn't get completely deformed on impact or something. Probably better if they used mercury (Here take explosive damage and mercury poisoning).

Mass reactive: Seems to be a lot of effort to put a sonar system into a bolt, just to activate a fuse.I'm not saying it's a bad idea but there are easier options.

Have you seen a bolt round it's quite round and it does not have to puncture hundreds of millimeters of armour. For killing someone in power armour and the table top performance a small(20mm) HEAT round makes sense to me.
A small missilette with an AP head (uranium(because it's crystalline structure self sharpens, can be swapped out with something similar and not radioactive)/adamantium/diamond/tungsten(even though it self blunts) would make sense in this context)HE charge also makes sense, but there is no depiction of the bolter firing, slim, long rocket projectiles that are fin stablised.

The reason why an RPG is so bulbous is so the shaped charge is bigger. Bigger charge, more penetration. 70-105mm in diameter. Anyways. Velocity don't matter with HEAT, so it's as effective as a 105 HEAT round. In WW2 I think HEAT rounds had around twice effectiveness, relative to diameter. German 75mm rounds could puncture 150mm of Rolled Homogenous Armour on a flat surface. Churchill MK 7 had 152mm on a flat surface. So if it were using WW2 HEAT tech it'd puncture 210mm RHA on a flat surface(obviously it is going to be more than this using post war HEAT tech).

Cap could be filled with plastic, or just a hollow tip behind the jacket of the shell. You could then put poison/etc in said hollow cap and therefore make more specialised ammo without the drawbacks. Although you'd want it potent. Something nice like a coagulant that also effects the nervous system.
I guess mercury would give extra weight, and if you have something with a rocket strapped to it, extra weight is just momentum... Then again regular old lead works pretty well.


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Main issue I have with a HEAT round, is the Marine is wearing the black carapace under his armour, and well his armour is big and bulky. So it is entirely possible that in key areas there is a space between them and you effectively have spaced armour.

A heat round would make a bunch more sense for piercing SM armour, although as mentioned previously you may need a double shaped charge. Hesh wouldn't really be appropriate for combating space marines as there is no empty space for the inner armour to spall into.


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See I always imagined their armour to be quite close to their body. Obviously it needs room to allow for muscle contractions, but I still think it would be quite tight fitting.

A shockwave powerful.enough to spall chunks off the inside of armour plate is likely to.do.relatively unpleasant things to internal organs.

With regards to shaped charges penetrating SM armor, in general, I'd think anything in Bolter realm size would be too small to reliably manage a meaningful Munroe effect to form a sufficient penetrator. I don't ever think I've seen a shaped charge of any sort below a certain size threshold, though I make no claims to being such an expert.

 Flinty wrote:
A shockwave powerful.enough to spall chunks off the inside of armour plate is likely to.do.relatively unpleasant things to internal organs.

This was something that always struck me as odd with the old AP system. Yeah, CaptainHeroHammer's armor might no be physically breached by an explosive rocket or massive crushing claw or impact hammer slam, but his ribcage and organs probably aren't as intact as the armor

Um, guys, bolters aren't designed to be good against space marine armour. It's actually mentioned in some of the lore that they aren't good against it. Marines were never meant to fight other marines. That's why bolters have always been worth feth all against space marine armour saves.

In all fairness, they're extremely inconsistent about that. Bolters seem to be about as effective as whatever any particular author needs them to be

We have bolters that often seem to effortlessly sycthe down marines in many HH books, practically every bolter in the Ultramarines movie ignored armor, etc

But do we really want to use that movie as an example of anything? And bad writing is bad writing, whether it's in the HH or anything else.

I don't think you need a really sophisticated system to detonate the bolt after penetration. If you know the normal velocity of a bolt and how far you want it to penetrate, all you have to do is have a timed fuse exploding the corresponding time later. It won't be always perfectly accurate, but that should be good enough.

In 2012 there was apparently a 6 axis accelerometer in a 3 x 3 x 0.9mm package. Looks like there are packages down to 2 x 2 x 1mm or less now.

Such a thing is not going to affect payload of a 20mm round that much. Add between 10,000 and 20,000 years of progress, and a true mass reactive detonator doesnt seem too far fetched.

Yeah, you could design something very "simple" considering future tech : when the accelerometer measures the acceleration of the bolt being shot, it arms the charge. When it measures the deceleration of the bolt hitting something, it detonates the charge after 0.01 second, or whatever time is needed to travel an inch or so into the target. It doesn't take complicated electronics to do that. Actually I wouldn't be surprised if something like that could be done with current technology. Which makes me think that a weapon as brutal as a bolter would probably break all kinds of international conventions.

 Vaktathi wrote:
With regards to shaped charges penetrating SM armor, in general, I'd think anything in Bolter realm size would be too small to reliably manage a meaningful Munroe effect to form a sufficient penetrator. I don't ever think I've seen a shaped charge of any sort below a certain size threshold, though I make no claims to being such an expert.

 Flinty wrote:
A shockwave powerful.enough to spall chunks off the inside of armour plate is likely to.do.relatively unpleasant things to internal organs.

This was something that always struck me as odd with the old AP system. Yeah, CaptainHeroHammer's armor might no be physically breached by an explosive rocket or massive crushing claw or impact hammer slam, but his ribcage and organs probably aren't as intact as the armor

There are some pretty small shaped charges that I've seen go through many inches. In our display stuff we had a block of steel plates each about half an inch thick, about 7 or 8 stacked together, and cut away to show the path the molten jet made through them, and that was from a disk about an inch in diameter or so.





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Gadzilla666 wrote:
Um, guys, bolters aren't designed to be good against space marine armour. It's actually mentioned in some of the lore that they aren't good against it. Marines were never meant to fight other marines. That's why bolters have always been worth feth all against space marine armour saves.

Which is dumb.. Yeah heresy bolters you can understand, but you'd think in 10k years they'd design something to pierce SM armour, for all those chaos dudes knocking about...

Well if a bolter ain't supposed to be good against heavy infantry like marines, I'm failing to see the value in the system at all. It needs to offer something. And surely you'd just manufacture better AP ammo.

Close in air defence platforms can program munitions to burst at the right distance, to say hit an incoming missile with flack blast, so I guess in the future that tech could be adapted to infantry weapons

 queen_annes_revenge wrote:

Gadzilla666 wrote:
Um, guys, bolters aren't designed to be good against space marine armour. It's actually mentioned in some of the lore that they aren't good against it. Marines were never meant to fight other marines. That's why bolters have always been worth feth all against space marine armour saves.

Which is dumb.. Yeah heresy bolters you can understand, but you'd think in 10k years they'd design something to pierce SM armour, for all those chaos dudes knocking about...

The lack of innovation and creativity is part of the setting. Besides, that's what plasma, melta, and heavy projectile weapons like auto-cannons are for.


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 OldMate wrote:
Well if a bolter ain't supposed to be good against heavy infantry like marines, I'm failing to see the value in the system at all. It needs to offer something. And surely you'd just manufacture better AP ammo.

Close in air defence platforms can program munitions to burst at the right distance, to say hit an incoming missile with flack blast, so I guess in the future that tech could be adapted to infantry weapons

It's a weapon designed for shock troops to be used on inferiorly armored opponents, just like chain weapons. For use against heavy infantry see above.

I presumed the Bolter was originally designed for use against Orks.

Tygre wrote:
I presumed the Bolter was originally designed for use against Orks.

It's pretty clear that marines were built mostly to wade through the absolute deluge of Orks that errupted after the Eldar fall destroyed the automaton armies that kept them at bay. Orks are far and away the most common alien species encountered in the galaxy.

Chainswords, exploding bolts, heavy bolters, missile launchers etc are all very effectively designed to counter the highly resilient Ork physiology.

When what you need dead is a hardy & tough as an Ork, a bolter makes perfect sense.

Plasma and auto cannons are not rapid fire service weapons. The heavy bolter is more analogous to a machinegun(especially in the hands of devistators) and the bolter a service rifle. The plasma gun and auto cannon have never been depicted as putting sheets of fire down range, which is actually proven to be what you need when faced by a determined enemy, while the bolter has.

You'd want a rapid fire service/suppression weapon which can be employed more often(and orks do classify as being heavy infantry as well considering they are generally as big as a marine and about as strong and sometimes come in more armoured varieties) plasma weapons are also quite dangerous and much more expensive. So a more suitable service weapon, even when combating marines would be a bolter/heavy bolter for general purpose and suppression.



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If a bolter is not designed to puncture armour, why not use a grenade launcher or grenade machinegun? It'd make more sense than trying to close with the beasts.

The vast majority of orks have poor armour. Bolters are designed to cause massive physical trauma to poorly armoured troops, which is what you want against a creature as capable of surviving physical damage as an ork. A service rifle or machine gun is meant to be used against enemy troops. For more armoured targets specialized weapons would be used. So a bolter is an excellent service rifle for use against orks.

 queen_annes_revenge wrote:
but you'd think in 10k years they'd design something to pierce SM armour, for all those chaos dudes knocking about...

They have. They're called Vengeance rounds.

They're hardly standard issue.

Neither are heretic astartes. Standard bolt rounds work fine for what marines would see the most of: human heretics and xenos scum.

They could have fooled me with renegades being an index and chaos cultists being a unit and not faction... I agree. But I'd still think the bolter would be better at puncturing armour. Perhaps it breaches the marine armour, but the armour protects key area ie head chest, and shoulders(because PAULDRONS!!! and you're combat ineffective when your arms get blown off I guess...)

Slayer6 wrote:
This coming at the time when the LRBT was determined to have a 120mm cannon - the barrel muzzle is significantly bigger than a Guardsman's whole head...

Let's all repeat the mantra here:

Science Fiction Authors Have No Sense Of Scale. This is no less true of small scale things than it is of large scale things.

Also, if it's as round as a guardsman's head you can't possibly accidentally break it.




Next minute...

 OldMate wrote:
They could have fooled me with renegades being an index and chaos cultists being a unit and not faction... I agree. But I'd still think the bolter would be better at puncturing armour. Perhaps it breaches the marine armour, but the armour protects key area ie head chest, and shoulders(because PAULDRONS!!! and you're combat ineffective when your arms get blown off I guess...)

Well the pauldrons used to be replaceable. If your advancing, which is a marines want. Your giant shoulder pad is gonna be first.
They call them pauldrons. But theyre more portable shoulder bastions really.

The bolter was designed to smash the ork. No one else was floating around the time.

If the bolter was desinged to kill the orc and not really armoured foes it does not need to be rocket powered (especially as an assault weapon) The rocket only adds velocity, which is not really needed against a lightly armoured foe like the orc. sure they have tough skin, but you can kill them with bayonets, so that says enough already. A bullet should have no issues.

I know it is much more mundane but it would make sense for it to just be a big ballistic weapon, packing payload ammo.

If I wanted to kill power armoured astares at long and close ranges on the other hand a hybrid conventional ballistic and rocket projectile with AP payload ammo. Which is what I mistook the bolter for.

Bigger weapons have bigger recoil. Especially if you want follow up shots. A 0.5 cal MG like the Browning is not really "single person usable" and 0.75 is 50% bigger. A rocket allows it to have a lower usable recoil and still have an effective combat range.

Of course astartes were only considered potential targets when the Heresy started and bolters were designed long beforehand.

firing 7.62x51mm in full auto is a handful for me (2m tall 115kg), a ma deuce would be similarly uncontrollable for anyone not astartes/ogryn. especially being combat effective. the rocket assist would definately help w maintaining target lock on something moving(i.e.ork, gaunt, spawn, etc) or dumbass cultists. Having the autosenses linked to the projectile would help with killing stuff. Black carapace integration would be even more effective.

A marine is extremely buff super soldier. They should be able to handle a bit of recoil. Besides, look at the AA 12 , efficient recoil countering systems means you can fire it pretty much single handed. If we can do that with an automatic 12 gauge shotgun (18.5mm), I think futuretechmagic can do that with a low velocity 20mm.

A rocket needs space to build momentum, space you don't have in a assault weapon, it does not have the explosive speed of gunpowder and other such propellants.


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Racerguy180 wrote:
firing 7.62x51mm in full auto is a handful for me (2m tall 115kg), a ma deuce would be similarly uncontrollable for anyone not astartes/ogryn. especially being combat effective. the rocket assist would definately help w maintaining target lock on something moving(i.e.ork, gaunt, spawn, etc) or dumbass cultists. Having the autosenses linked to the projectile would help with killing stuff. Black carapace integration would be even more effective.

I wish I could have such fun guns over here although specialist rounds (primaris have some...) do have tracking and targeting ability so the suggestion is regular rounds would not.

Yeah the rocket is only really suitable for long distances. I think its a case of them making something that sounded cool, especially in the 80s, but doesnt really stand up to modern scrutiny (I know its the future, sci fi yeah blah blah)

Shotgun range is not ideal for an assault rifle however. Something to boost the range is needed. The rocket does not necessarily need to accelerate the round, but slow down its deceleration.

Low velocity on impact would also mean low penetration. And you still would want to penetrate flak type armour.

With future tech you would think that they would just invent something (maybe Grav based) to cope with the recoil.

Hence low velocity 20mm, I'm talking more a shortened cannon round with advanced recoil compensation instead of a shotgun round.

Extra range would be a good reason to have that rocket propulsion. This is a technology that's actually used on some artillery shells, where you have plenty of time after the shell has left the cannon to get that boost and fly a few extra kilometers.

Also, shooting bigger projectiles means you need bigger explosions and a barrel can only handle so much pressure before it bursts, so rocket propulsion is a way to move heavier loads. Of course, this applies more to massive artillery cannons than to rifles... but you need to have something to make the rifles science fictiony after all

 Tiennos wrote:
Extra range would be a good reason to have that rocket propulsion. This is a technology that's actually used on some artillery shells, where you have plenty of time after the shell has left the cannon to get that boost and fly a few extra kilometers.

Also, shooting bigger projectiles means you need bigger explosions and a barrel can only handle so much pressure before it bursts, so rocket propulsion is a way to move heavier loads. Of course, this applies more to massive artillery cannons than to rifles... but you need to have something to make the rifles science fictiony after all

I do remember hearing that modern artillery rounds do have tiny rockets in them. It's just to help defeat drag as air rushes over the back of the shell. As tiny as the rockets are I believe it added 25% to the range of the projectile.

I also think that bolters would work like an automatic 10 gauge magnum shotgun . True, it would be bad for an assault rifle, but I dont think it much matters. Most infantry engagements are around 100 meters. Beyond 100m is usually the work space of heavy weapons and artillery. Space marines deploy as close to their enemies as possible and wear heavy armor. An effective range of 200 meters would be fine. SMs aren't snipers. That's neophyte work. Leave it to the scout company.

I agree that "science fiction" would fill in the gaps as far as range goes. Maybe sci fi could take the bolter's range out to 300m. There would probably be a small guidance system too. Nothing too accurate, it is the Grim Dark after all.

 Red Marine wrote:

I do remember hearing that modern artillery rounds do have tiny rockets in them. It's just to help defeat drag as air rushes over the back of the shell. As tiny as the rockets are I believe it added 25% to the range of the projectile.

Those are base bleed munitions. Rocket assisted projectiles are different and add velocity rather than reducing drag. Base bleed was invented in the 1960's; and Rocket Assisted Projectiles in WW2.

Yeah, given marines have a helmet that should be kitted with optical and targeting/tracking systems, a hybrid rocket/ballistic powered munition should kill people pretty consistently out to 1000m and beyond.

If it has appropriate ammo it should kill astartes too.

We are talking about super soldiers that have nothing better to do than thousands of hours of range time.

Bolter is a let down basically.

I dont think the Bolter is a let down. I think the writers just try to make the Bolter too many things for too many people/ scenarios. In some stories it's a sniper rifle. In others a heavy machine gun. If they settled on a number of positive and negative features for the gun AND gave it table top rules supporting it, the Fandom wouldn't argue this point so often.

Debating what it's real world abilities might be is fun, but I think it comes down to head cannon. What stats in the fluff you like combined with real guns and the stats in the TT rules. For me the Bolter is akin to a heavy submachine gun. Its range should probably be shorter but its performance should be a little better. Probably something more akin to a shuriken catapult. Oddly, I always thought CWE Guardians should have had a more conventional 24" rapid fire weapon.

Personally I feel the astartes are the best and deserve the best. Not some glorified cut down heavy stubber.

I see the bolter as a kind of carbine, a service rifle geared towards close engagment.
But I believe it should be able to combat armoured enemies out to 1km. It should be very accurate (these things are artificer made, in other words custom barrels, bedding ect, work carried out by the finest gunsmiths from entire sectors) mechanically the astartes pattern* bolter should be a work of art.

Couple that with the helmet's battle systems and a veteran with thousands of hours of range time and thousands of hours of combat experience and what you should have in my view, what every spacemarine is. Very lethal, very efficient shock trooper. Also I disregard the notion that is a 4 shot burst fire weapon. Because a spacemarine, or scout, should be able to send as many rounds down range as they want using semi/fully auto, and have them hit where they want. If not how are they super human, and how would you justify their selection processes and combat training? Might as well give scions their accuracy roll...

*(because I refuse to believe a spacemarine and a guardsman have the same sized/calibre gun)