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 Grey Templar wrote:
Where does it say that bolters don't all use the same ammo? Where is the myth of different calibers coming from?

Forgeworld Heresy Books, Phobos Pattern Bolter is 0.6 cal. It's in one of the first 3, don't remember and am too lazy too look now. One of the reddish armour schemes with weapons next to them.
I dont recall exactly, but i think one of the boltpistols was 0.5 cal

 Grey Templar wrote:
The bolter is a perfectly acceptable weapon. Just because its lackluster in the game doesn't mean its bad in the fluff. Game =/= fluff.

In Deathwatch the bolter is pretty damn good. It actually does more damage on average to soft targets than a Plasma gun does(2D10+5 vs 1D10+9). It just has a better Pen value. Bolters also roll an additional D10 for damage and drop the lowest because they have the Tearing rule.

Yeah, I play Deathwatch a lot. I am a GM. The Deathwatch bolters are perfect, just how SM bolters should be.

Do note that they are significantly more powerful than human bolters, though. Human bolters only roll 1d10 for damage. The difference is considerable.

The plasma gun is also very powerful once you count in maximal mode.

actually i was half wrong... here is the picture

book 1 betrayal, tigris pattern boltung 0.6 , Phobos 0.7 (instead of 0.75)

Now where is that proof for humans and astartes all having the same ammo you owe me?

Only War bolters are 1d10+5/tearing

Hellguns are 1d10+4

Lasguns are 1d10+3 with variable setting

 Keep wrote:

 Grey Templar wrote:
Where does it say that bolters don't all use the same ammo? Where is the myth of different calibers coming from?

Forgeworld Heresy Books, Phobos Pattern Bolter is 0.6 cal. It's in one of the first 3, don't remember and am too lazy too look now. One of the reddish armour schemes with weapons next to them.
I dont recall exactly, but i think one of the boltpistols was 0.5 cal

Interesting. I'd chalk it up to GW not knowing their own fluff.

Interesting. I'd chalk it up to GW not knowing their own fluff.

Why? It makes no bloody sense to have just one caliber for a given weapon type. It's also uninspired and boring.
And that's what forgeworld recognized and changed. Well done forgeworld, once more you produced background information that is feasible and makes sense... because apparently nobody else has the capability to come up with feasible technical NEW information... or has the guts
Also... fluff changes over time. Bolts aren't exclusively caseless rocket propelled projectiles anymore, they have cases that eject. Bolters that do exclusively have casless rpp's may still be around however, it's never been falsified.

Different chapters more than likely have different caliber preferences.

You keep arguing that it's a waste of a Marine's strength because a normal man can fire them...
How long do you think those normal men are going to be able to fire them? Space Marines are massively strong and have Power Armour, with strength-enhancing servos and recoil compensators. The handful of humans, such as Senior Officers, have had years of training with a bolter, and will rarely use it as they lead from the rear. Likewise, Inq retinues are bodyguardsm neither are involved in protracted engagements like the standard IG. Trying to use a bolter for days or months at a time would likely end ip taking the shoulder off a normal man, especially considering it has no stock to brace against. Then all the accuracy, ammo and morale goes out the window.

Bolters are fine for Space Marines. Its the perfect medium between accuracy, firepower, mobility, RoF and ammo consumption.
They have a version for higher RoF, the stormbolter. Its widely inacurate compared to the standard bolter, with a much higher consumption of the same ammo, and judging by the Sternguard Vets rules, it's likely the ammo consumption is too high to justify the use of Special Ammo.
A more mobile version is the pistol, with lower everything else.
A Heavy Bolter is the next stage, with much higher Firepower and RoF but ammo consumption is much higher, mobility limited, expensive and tactically limiting.


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 Keep wrote:

 Grey Templar wrote:
Where does it say that bolters don't all use the same ammo? Where is the myth of different calibers coming from?

Forgeworld Heresy Books, Phobos Pattern Bolter is 0.6 cal. It's in one of the first 3, don't remember and am too lazy too look now. One of the reddish armour schemes with weapons next to them.
I dont recall exactly, but i think one of the boltpistols was 0.5 cal

The Phobos pattern is most commonly associated with the Mk2 Crusade Armour, according to FW website IIRC. Its shown being held by the Mk2 in the last 2 SM codexes, certainly. That would suggest its a much earlier version of the current weapon. Perhaps GW mean .75 and focus specifically on the Godwyn, seeing as its common with Mk7 armour, and apparently only Mk6 and 7 exist to GW.

Marine armour is powered by a fusion reactor. It would seem a waste to arm them with anything less than multi-lasers. If jetbikes can do it


Automatically Appended Next Post:
Also Marines are armed with bolters because they have always been armed with bolters. It deosn't have to make sense because its part of the original aesthetic. The background fluff has crept up around and about the original design decisions from Rogue Trader where Marines were not what they are now and bolters were used because they were loud messy and effective, rather than being the precisely perfect weapon to arm post-human mega-super-soldiers with.

You keep arguing that it's a waste of a Marine's strength because a normal man can fire them...
How long do you think those normal men are going to be able to fire them? Space Marines are massively strong and have Power Armour, with strength-enhancing servos and recoil compensators.

No you dont understand - i argued that IF a human would be able to use a regular marine bolter, it would indicate that the marine doesn't have a weapon that is not properly scaled to him. Ergo, since the later is not so likely, and stuff related to 0.75 is too big [and heavy ]to be handled by humans (see my post couple of pages back) with any good effect, human bolters would use weaker and smaller ammunition (for more reasons then just weight). That is the conclusion i have. Not that Marine bolters are not enough for Marines - so we are actually on the same page here.

The Phobos pattern is most commonly associated with the Mk2 Crusade Armour

So? That doesn't change the fact that different calibers have existed. Therefore they are still around in some numbers at least. Including the Tigris pattern and the Boltpistol. Those are only the patterns we know about. There may be more patterns, which could pop up at any time from FW. If different calibers exist for marine bolters, it is certainly a thing for non-PA human bolters as well. And other weapons (heavy stubber for example) as well.

 Keep wrote:

You keep arguing that it's a waste of a Marine's strength because a normal man can fire them...
How long do you think those normal men are going to be able to fire them? Space Marines are massively strong and have Power Armour, with strength-enhancing servos and recoil compensators.

No you dont understand - i argued that IF a human would be able to use a regular marine bolter, it would indicate that the marine doesn't have a weapon that is not properly scaled to him. Ergo, since the later is not so likely, and stuff related to 0.75 is too big [and heavy ]to be handled by humans (see my post couple of pages back) with any good effect, human bolters would use weaker and smaller ammunition (for more reasons then just weight). That is the conclusion i have. Not that Marine bolters are not enough for Marines - so we are actually on the same page here.

The Phobos pattern is most commonly associated with the Mk2 Crusade Armour

So? That doesn't change the fact that different calibers have existed. Therefore they are still around in some numbers at least. Including the Tigris pattern and the Boltpistol. Those are only the patterns we know about. There may be more patterns, which could pop up at any time from FW. If different calibers exist for marine bolters, it is certainly a thing for non-PA human bolters as well. And other weapons (heavy stubber for example) as well.

There are many more patterns. There is the Umbra pattern which replaced the Phobos, the Umbra-Ferrox, common with the MkIV armour and featuring a large box magazine, and the Tigrus which went with the Mk4 but then the Mk5 during the HH.

 reptilelover1995 wrote:
Thanks for the advice. I may need help drawing up a revised diagram to show more detail for those other parts, and other opinions or ideas are always welcome and encouraged to get more than one perspective.

I don't think that metallic hydrogen would be feasible within something that small, just because you'd have to somehow generate the immense pressures found within a gas giant in order to compress the hydrogen enough to make metallic hydrogen. Plus, I'm pretty sure that the expansion once the target was hit would be so massive it would pose a danger to anyone within a significant radius. I don't know for sure though.

It might not at all be feasible, which is why I added the caveat, but its also a possible way to reconcile all the differences in the fluff WRT bolters. 'depleted deuterium' is a bit hard to explain away, especially when you have FFG and Forgeworld (in the Imperial armour suppelment for Space Marines) both saying that bolter cores are dense (with FW adding that the core adds to penetration, and FFG saying its 'metallic.') THere's also the issue that with some observed results of bolters you need a pretty powerful explosive (eg blowing apart the entire upper torso, even after penetration. Mythbusters has tested that informally in years past and you need roughly something on the order of a stick of dynamite or a grenade to accomplish.) You might be able to handwave it as being some sort of 'reactive metal' material (tehre has been speculation on making high density reactive materials that mean you could build a shell out of 'explosive/incendiary' material in addition to its explosive charge, but nothing exactly 'dense core' or even explosive, at least as I understand it.)

Otherwise I guess you start have to selectively picking and choosing what the 'true' fluff is, but I think threads of this nature show not everyone will agree what the 'truth' in such matters is and that will also get in the way of making an argument that will persuade a broad cross-section of people. Also, I'm not sure what you consider a 'significant radius' for danger though or why it would be any more dangerous than an explosive of comparable power.

 Keep wrote:

Interesting. I'd chalk it up to GW not knowing their own fluff.

Why? It makes no bloody sense to have just one caliber for a given weapon type. It's also uninspired and boring.
And that's what forgeworld recognized and changed. Well done forgeworld, once more you produced background information that is feasible and makes sense... because apparently nobody else has the capability to come up with feasible technical NEW information... or has the guts
Also... fluff changes over time. Bolts aren't exclusively caseless rocket propelled projectiles anymore, they have cases that eject. Bolters that do exclusively have casless rpp's may still be around however, it's never been falsified.

And the other way too. Xenos Hunters clarified some boltguns are .998 caliber (cue discussion over validity of BL sources):

"More effective is the 0.998 calibre boltgun. Standard issue within the Adeptus Astartes, although rarely employed elsewhere within the Imperial military. Observe."
The attachment on the servo-arm blazed away, chugging mass-reactive shells at the creature. They impacted and shredded the gaunt’s talon arm from its body almost as an afterthought; the scything blade-limb clattered to the deck as the alien obscenity screeched in instinctual fury rather than pain. Its shoulder was nothing more than a ruined stump of spurting gristle."

I'd guess it depends on what they're going for. Most assault rifles I know of can be rechambered for different calibers just by swapping out components, so I imagine bolters can be as well. It would explain the highly variable effects and performance of the weapon at least.

As an aside, was that the same book (or even page) that had the AStartes meltagun with the megathule rating? I kind of broke out cackling when I saw that and how that might be interpreted.

0.998 seems a bit large though, especially since heavy bolters are supposed to be 1.0 calabre.


Really, I don't see why most imperium owned bolters having the same bolts is that unbelievable. It's like NATO standardization, but at a much larger scale.

0.998 makes sense for an astartes bolter, mind you.

HBs still have more range and RoF.

No it does not. Heavy bolters are powerful enough that even space marines have to brace them, normal humans require a tripod or alike to fire them.

And, AFAIK, the Astartes MK Vb Godwyn pattern bolter fires .75 calibre rounds.

0.998 was a pattern, not a caliber, people keep mixing up the two.

 Co'tor Shas wrote:
Really, I don't see why most imperium owned bolters having the same bolts is that unbelievable. It's like NATO standardization, but at a much larger scale.

Because letting Imperial soldiers throw expensive astartes grade ammunition around seems like a waste of valuable ressources. Much more sensible to have cheaper and less complex ammo, suited to IA's particular needs, particulary since Heavy Bolters are ammo-hungry and often used.


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 Co'tor Shas wrote:
No it does not. Heavy bolters are powerful enough that even space marines have to brace them, normal humans require a tripod or alike to fire them.

Elysians dont use a tripod. Steel legion doesnt use a tripod either. So either they use a smaller round then space marines and the other heavy bolters. Or Cadians are a bunch of whimps and Marines just like to act cool and rambo

Elysians have bipods, which is close enough. And the Steel Legion brace it on the ground or sandbags.

In OW every single heavy weapons guy can run around and accurately fire his HB.

No, you have to spend half an action to brace the weapon. And then fire. Or move-brace-aim-shoot.

You'll be firing at a rather nasty penalty if you're unbraced, and on top of that, there's a quite a few heavy weapons that are full auto only, meaning more penalties.

Edit: Unless you're a sentry, I think they can have their companion brace the weapon for e'm, letting them do brace-aim-fire in a turn.

A heavy bolter is mostly just heavy and cumbersome. The round itself, despite being very wide, has almost no charge. The recoil would be hefty but might not be as bad as even a .50 BMG. It's just enough charge to give lethal velocity out of the barrel before the self propellant kicks in and stabilizes while accelerating further.

On the subject of different bolts for different guns, I can imagine with a cult as devoted as the mechanicum that each bolter model has a special bolt that works best with it. The charge for each bolt is probably designed to have a "slow burn" so that it burns itself entirely out exactly as the bolt leaves the barrel of the chosen bolter.

This is my headcanon anyway.

 Bobthehero wrote:
No, you have to spend half an action to brace the weapon. And then fire. Or move-brace-aim-shoot.

You'll be firing at a rather nasty penalty if you're unbraced, and on top of that, there's a quite a few heavy weapons that are full auto only, meaning more penalties.

Edit: Unless you're a sentry, I think they can have their companion brace the weapon for e'm, letting them do brace-aim-fire in a turn.

Except as a heavy weapons guy you can access Bulging Biceps right from the start.

 Bobthehero wrote:
Elysians have bipods, which is close enough. And the Steel Legion brace it on the ground or sandbags.

Close enough? Mount a 50cal or a Mk19 on a bipod, add a stock and try your luck. I don't think you would say "close enough" after that experience.
They have visually different Heavy Bolters then the plastic cadians have. Cadian Hvy Weapon team Hvy Bolters are huge compared to other heavy bolters.

Connor MacLeod wrote:

 reptilelover1995 wrote:
Thanks for the advice. I may need help drawing up a revised diagram to show more detail for those other parts, and other opinions or ideas are always welcome and encouraged to get more than one perspective.

I don't think that metallic hydrogen would be feasible within something that small, just because you'd have to somehow generate the immense pressures found within a gas giant in order to compress the hydrogen enough to make metallic hydrogen. Plus, I'm pretty sure that the expansion once the target was hit would be so massive it would pose a danger to anyone within a significant radius. I don't know for sure though.

It might not at all be feasible, which is why I added the caveat, but its also a possible way to reconcile all the differences in the fluff WRT bolters. 'depleted deuterium' is a bit hard to explain away, especially when you have FFG and Forgeworld (in the Imperial armour suppelment for Space Marines) both saying that bolter cores are dense (with FW adding that the core adds to penetration, and FFG saying its 'metallic.') THere's also the issue that with some observed results of bolters you need a pretty powerful explosive (eg blowing apart the entire upper torso, even after penetration. Mythbusters has tested that informally in years past and you need roughly something on the order of a stick of dynamite or a grenade to accomplish.) You might be able to handwave it as being some sort of 'reactive metal' material (tehre has been speculation on making high density reactive materials that mean you could build a shell out of 'explosive/incendiary' material in addition to its explosive charge, but nothing exactly 'dense core' or even explosive, at least as I understand it.)

Otherwise I guess you start have to selectively picking and choosing what the 'true' fluff is, but I think threads of this nature show not everyone will agree what the 'truth' in such matters is and that will also get in the way of making an argument that will persuade a broad cross-section of people. Also, I'm not sure what you consider a 'significant radius' for danger though or why it would be any more dangerous than an explosive of comparable power.

Part of the point of this thread is simply to look at the supposed effects, and think of ways that modern technology could replicate those devices (if possible of course). If that contradicts existing fluff, that doesn't matter because here we're talking with function in mind rather than just writing about what sounds coolest. I'd love to come up with a functioning bolter, but I really need that help. At this point I think fluff can be thrown out the window because the rest of the work is functional and we know what to device does, we just need to figure out how to get it to do it.

Also, I'm working on a heavy flamer schematic, since that technology obviously exists in modern times. I'm just wondering about the internal mechanics of the flamethrower, and what those holes are for on the end of the nozzle. I thought they might help vent the heat buildup, but that would mean that the flamer fuel would be spraying out of those as well as out of the end of the weapon, leading to a very bad day for whoever's wielding it. Suggestions and whatnot are appreciated.

40K flamers are nothing like modern day flamers. They work on the same concept, but 40K "prometheium" can mean anything from gasoline to reactor fuel.

With regards to the flamer, I suspects its similar to air-cooled MGs like the M1919. The holes arn't actually part of the barrel of the weapon. If we were to remove the big block at the end of the flamer it would likely look nuch like a rifle barrel. Those holes then go through that block to bring cold air to the outside of the cylinder of the barrel. The block itself acts as the heatsink, meaning the ferocious heat of the flamer is not focused on a tiny tube of a barrel but instead on a thick block of plasteel and so won't melt, as well as being highly exposed to the air.
On the other hand, it could be the holes don't reach the barrel at all but actually suck in air for the pilot light.

rifled ammunition (that is, something that uses spin stabilization) has certain length to diameter limits in order to actually work. Typically its around 5 or 6 to 1 - or rather, if you have a 20mm bolt round or so, the maximum length you could have for rifled ammo is 100-120mm, if that. In theory (and that is THEORY) you can stabilize it better if you spin it much faster (different rifling) but I'm not sure a.) how fast you have to spin b.) if it actually works, c.) the short barrels of bolters could make it work.) although some gun launched anti-tank missiles have achieved greater L/D ratios (but most if not all also had fins I believe. Shillelagh might not have, I'd have to go back and check, but evne if not they're also guided and most bolt rounds aren't.)

25mm isn't that much bigger than 20mm really (literally a few mm) as far as caliber goes, but I suppose you could say .75 cal is strictly for astartes grade caliber and other human-sized bolters typically either are designed around astartes ammo (making sacrifices to do so) or use lower caliber ammo (.50 or .60 cal, say.) Probably would have to do that to have any number of shots in the gun and have a normal person able to carry it that way, anyhow. I should also note 25mm is also considered the minimum acceptable effective 'grenade' caliber - 20mm are simply too small and light to be effective (and even 25mm needs to be guided to optimize detonation distance, as I recall.)

 reptilelover1995 wrote:

Part of the point of this thread is simply to look at the supposed effects, and think of ways that modern technology could replicate those devices (if possible of course). If that contradicts existing fluff, that doesn't matter because here we're talking with function in mind rather than just writing about what sounds coolest. I'd love to come up with a functioning bolter, but I really need that help. At this point I think fluff can be thrown out the window because the rest of the work is functional and we know what to device does, we just need to figure out how to get it to do it.

Understood, but in my experience you can't disregard people's perceptions of what is the 'correct' fluff in these things because it will simply bog down attempts at analysis as disputes break out and the 'value' of an answer will invariably rely on consensus if it is meant to be publicly displayed. I mean look at the 'caliber' issue above. Additionally, there has to be limits to disregarding fluff not only just because it can provoke disputes, but also because at some point the 'analysis' will become completely arbitrary. I mean how far do you disregard fluff to make a 'bolter' work, and yet still have it be in a sense a bolter and not just a really large-caliber slugthrower?

I'd say that the vast majority of stuff in 40K could be rationalized 'somehow' even with inconsistencies (like most weapons represent a category of weapons. Like how auto- and stub- and missile/grenade weapons can represent an entire series of calibers, features, designs, weighs/sizes, etc. rather than a single weapon, you can have bolters, lasguns, plasma, melta, etc. all resemble the similar. That idea along with the technological variation/inconsistency across the Imperium gives tons of rationale for explaining things, but not everyone will neccesarily 'agree' that it is the right answer unless you present it a certain way or make allowances. It's kind of a juggling contest.

Also, I'm working on a heavy flamer schematic, since that technology obviously exists in modern times. I'm just wondering about the internal mechanics of the flamethrower, and what those holes are for on the end of the nozzle. I thought they might help vent the heat buildup, but that would mean that the flamer fuel would be spraying out of those as well as out of the end of the weapon, leading to a very bad day for whoever's wielding it. Suggestions and whatnot are appreciated.

I suppose it depends on where the flamer in question originates from. We know there are some designs that closely approximate the real life equivalents in effect and design, but on the other hand you have tons of examples that have flamethrowers that can cremate people, or can be miniaturized down to rifle, pistol, or even digital weapon sizes yet function well (even if its just inflicting burns.) The far end (in either or both cases) requires a vastly better level of 'tech' in flamers than what we likely have and may even border on raygun. (like for the cremation flamers, I suspect they may be able to induce organic targets to spontaneously combust, contributing their own energy reserves to the cremation process in addition to whatever the flamer contributes. That could also help explain the ability ot miniaturize them as well, actually.) Think of a phaser that jets jellied incendiary fuel and slowly burns you to death rather than disintegration in seconds.

 Wyzilla wrote:
40K flamers are nothing like modern day flamers. They work on the same concept, but 40K "prometheium" can mean anything from gasoline to reactor fuel.

Actually they're exactly like modern day flame throwers.

Promethium = Any fuel derived from fossil fuels. Its very specific.

However, most Imperial vehicles run on Multi-fuel instead. Which does indeed cover a wide array of flammable liquids, ranging from artificially synthesized petrochemicals to biofuels to alcohol based fuels. Only important vehicles are run on Promethium, like Rhinos or Bikes. Most promethium is reserved for either use in weaponry or more important manufacturing processes, like lubrication. Its too rare to waste as a fuel for everything.

Connor MacLeod wrote:

25mm isn't that much bigger than 20mm really (literally a few mm) as far as caliber goes, but I suppose you could say .75 cal is strictly for astartes grade caliber and other human-sized bolters typically either are designed around astartes ammo (making sacrifices to do so) or use lower caliber ammo (.50 or .60 cal, say.) Probably would have to do that to have any number of shots in the gun and have a normal person able to carry it that way, anyhow.

Well difference is "just" +25% in diameter, but +56% in volume (cylinder with same heigth). So you can roughly have +56% more explosive. That's significant imo.

Connor MacLeod wrote:
I should also note 25mm is also considered the minimum acceptable effective 'grenade' caliber - 20mm are simply too small and light to be effective (and even 25mm needs to be guided to optimize detonation distance, as I recall.)

Yes for airburst/shrapnel 20mm wasn't deemed good enough. However, if the round only explodes on impact (as bolters supposedly do), that's a big difference. There are also explosive rounds for Nato 12.7mm rounds for example. So even with a smaller caliber bolt round, they would be pretty devestating (blowing arms off etc).

 Co'tor Shas wrote:
0.998 seems a bit large though, especially since heavy bolters are supposed to be 1.0 calabre.


Really, I don't see why most imperium owned bolters having the same bolts is that unbelievable. It's like NATO standardization, but at a much larger scale.

The IoM is in no way standard. They have some units fighting with rocks and sticks