40K Online

Main => Background => Topic started by: The Black Dahlia Murder on June 30, 2009, 11:10:12 AM

Title: Size of a bolter?
Post by: The Black Dahlia Murder on June 30, 2009, 11:10:12 AM
What are the dimensions of a Boltgun with a slickle clip?

Title: Re: Size of a bolter?
Post by: Wyddr on June 30, 2009, 12:01:52 PM
I believe it varies, depending on design. Some of the fluff describes the bolters the Space Marines carry as being very, very large, whereas the ones the Sisters of Battle carry are somewhat smaller.

I would suppose that your average bolter, given the dimensions of its ammunition, would be pretty large affairs. Figure about twice the bulk of your average assault rifle, maybe more, and probably two to three times as heavy.
Title: Re: Size of a bolter?
Post by: Koval, Master Verispex on June 30, 2009, 02:53:01 PM
A general answer is "very large"

Expanding on Wyddr's answer, though, take one of these (http://en.wikipedia.org/wiki/AK-47), and keep the length but multiply the other dimensions by two, mostly to accommodate its 0.75 caliber ammunition. Wyddr's mass estimate seems logical as well.

For Space Marine weaponry, add a third to all those "final" dimensions and mass, just as a general guideline.
Title: Re: Size of a bolter?
Post by: dragonclaw15 on June 30, 2009, 05:07:28 PM
Wyddr touches on this, but it is important to note that there are (at least) two classes of bolt weaponry - those carried by the Space Marines, and those carried by everybody else. Obviously those carried by Space Marines are bigger, and in proportion with their enhanced bodies, and those used by SOB or guard are smaller, with smaller shells to match.
Title: Re: Size of a bolter?
Post by: High Grandmaster smithmyster666 of the Grey Knights on June 30, 2009, 07:21:19 PM
the bolter uses .998 rounds according to DOW2. the .998 round is about the length of a uk size 9 foot so thats pretty huge. also the weapons size being proportional to current weapons would make it approximately 8ft long X 10" wide X 2ft high.
Title: Re: Size of a bolter?
Post by: Librarian Nikol on June 30, 2009, 08:07:04 PM
The problem I see is that I don't necessarily see the Bolter as an assault rifle, more like a quick-firing grenade launcher. a .75 round is really rather large, just under 20mm for metrics (like me), and the bolter round is an explosive thing. So I see Bolters less as assault rifles, more as scaled-down grenade launchers.

A big thing is the size of the round. Taking the .75 calibre (because I see that as more realistic), we have a round that (taking the garden variety 40mm grenades of today as a base) is 20mm diameter, and about 50mm high. That's a big, squat round, however you look at this, and the size of the magazine supports this somewhat. It's just not big enough to take a conventional rifle round (Very long vs small diameter). The barrel is also very short, suggesting a weapon that is not designed for accuracy, but just to 'point it in the right direction'. I remember reading somewhere that the Godwyn pattern bolter is smoothbore, but I can't be certain, but if it is, it reinforces the issue of the bolter really being a small grenade launcher.

Now, looking at the size, this all makes things a lot easier to understand. We can make a good estimate at the magazine size. The sickle magazine is meant to take 20-30 rounds. Now, stacked alternately like in modern firearms, and using the smaller number, this gives us a rough height of about 35cm, depending on how acute the stack is, and a width of about 5cm. That's big, and I'd say, roughly consistent with the size of the magazine on the models. a 30-round magazine has us sitting at about 50cm long magazine, which is just far too big, in my head.

Now, onto the internal mechanisms of the Bolter. If it uses a standard percussion cap firing system like modern firearms, we need somewhere for a firing pin and spring assembly. Then we need a holder for the shell, springs to push it into the breach and then pull back the empty case after firing. That's large, and I'm guessing takes up most of the rear mass of the bolter, considering the size of round and firing stresses. If it's electrically fired, we need a lot less working parts, and the size of the working parts will be reduced, so that they take up less space inside the weapon.
 Then we need all the gubbins included, like genetic grips and targeting systems, taking up yet more space inside the thing, almost too much space in my head, but GW don't do 'tru-scale' that coincides with the fluff, so that's understandable.

All in all, for the bolter, as a rough guess I'd say you're looking at a barrel length of about 45-55cm (working this out in my head), a body width of about 7-10cm and a height dependent on the magazine, but empty, I'd hazard a guess at 35cm high. Sounds very squat and fat for an assault rifle, but sounds about right for a 20mm high-velocity grenade launcher.

BUT, on the other hand, you could take all of what I've said and throw it out, because I don't live 38,000 years in the future and I don't know what kind of tech they have!

Hope this kind of helps...
Title: Re: Size of a bolter?
Post by: Lachdonin on June 30, 2009, 09:40:12 PM
Personaly, i think a percussion cap firing system is a little simplistic for one of the holy weapons in the Imperium. I've always imagined them working on something more like the electrical trigger of the Metal-Storm prototype weapons, but with a working loading mechanism. This alone would free up a good deal of space in the actual body of the weapon. As for the actual size... I don't have one on hand, but when i get home I'll measure the size of the model, and compare it proportionally to the standard 8-Foot Space Marine.

Again, GW doesn't really scale things right, but it may give us a bit of insight.
Title: Re: Size of a bolter?
Post by: Sayt on June 30, 2009, 09:51:26 PM
Personaly, i think a percussion cap firing system is a little simplistic for one of the holy weapons in the Imperium. I've always imagined them working on something more like the electrical trigger of the Metal-Storm prototype weapons, but with a working loading mechanism. This alone would free up a good deal of space in the actual body of the weapon. As for the actual size... I don't have one on hand, but when i get home I'll measure the size of the model, and compare it proportionally to the standard 8-Foot Space Marine.

Again, GW doesn't really scale things right, but it may give us a bit of insight.

This.

Also, if I recall correctly, Bolt rounds are Caseless ammunition, which, from my understanding, doesn't work with traditional "Hammer Action" firearms, depending on the propellant.   The are, essentially  these,  (http://en.wikipedia.org/wiki/Gyrojet)excepting that they're actually effective.  The Bolts are, essentially, miniature rockets, all the gun does is sest it's engire going/propel the bolt till the engines engage.
Title: Re: Size of a bolter?
Post by: dragonclaw15 on June 30, 2009, 10:27:22 PM
Notwithstanding the cased/caseless debate, everyone agrees that bolt shells are in effect miniature rockets. To that end, it would make sense if bolters are smoothbore (since the shells would stabilize themselves, by spinning or with fins, whatever). Also, then accuracy would not be affected by barrel length, which also explains why in old art or models you see bolters with the clips practically at the end of the barrel.
Title: Re: Size of a bolter?
Post by: Koval, Master Verispex on July 1, 2009, 03:47:37 AM
the bolter uses .998 rounds according to DOW2. the .998 round is about the length of a uk size 9 foot so thats pretty huge. also the weapons size being proportional to current weapons would make it approximately 8ft long X 10" wide X 2ft high.
I've just checked this myself -- you are getting mixed up with the date of issue. It is well documented in multiple fluff sources that a bolter fires .75 calibre shells.


Personaly, i think a percussion cap firing system is a little simplistic for one of the holy weapons in the Imperium. I've always imagined them working on something more like the electrical trigger of the Metal-Storm prototype weapons, but with a working loading mechanism. This alone would free up a good deal of space in the actual body of the weapon. As for the actual size... I don't have one on hand, but when i get home I'll measure the size of the model, and compare it proportionally to the standard 8-Foot Space Marine.

Again, GW doesn't really scale things right, but it may give us a bit of insight.

This.

Also, if I recall correctly, Bolt rounds are Caseless ammunition, which, from my understanding, doesn't work with traditional "Hammer Action" firearms, depending on the propellant.   The are, essentially  these,  (http://en.wikipedia.org/wiki/Gyrojet)excepting that they're actually effective.  The Bolts are, essentially, miniature rockets, all the gun does is sest it's engire going/propel the bolt till the engines engage.
Actually, they've got cases, otherwise they wouldn't have case ejection ports on the side. I agree with the rest.
Title: Re: Size of a bolter?
Post by: Seren Nos on July 1, 2009, 04:37:57 AM
I don't have one on hand, but when i get home I'll measure the size of the model, and compare it proportionally to the standard 8-Foot Space Marine.

Again, GW doesn't really scale things right, but it may give us a bit of insight.

Anyone fortunate enough to have been to the Warhammer World museum in Nottingham UK before the exhibits got scattered all over the world, would have seen the life size Marine and also the storm bolter they had on display. The Marine itself was probably about 7 foot tall, possibly 8. I'm speculating here because obviously I didn't measure it, but the boltgun would have to have been 24" long (the marine having to carry it 2-handed). The storm bolter is a massive weapon (esentially 2bolters together), the average human would have extreme difficulty even lifting it. Guessing again I would have put it at 30" long with musc more mass.

I'm not sure but the Marine Statue outside of GW UK HQ could be 1:1 scale. I don't have an internet picture hosting facility so I can't post a picture of it I have from earlier this year.
Title: Re: Size of a bolter?
Post by: Librarian Nikol on July 1, 2009, 05:53:07 AM
On the cased/caseless issue, I support the cased party for a number of reasons. Firstly, as Koval pointed out, there's a whacking great ejection port on the side of the bolter. Don't need that in a caseless weapon. Secondly, in a lot of the fluff images, including the masterfully done painting on the front of the old SMurf 'dex, you can clearly see shells coming out of the Bolters, and that's official cannon.

But then again, if they are electrically fired rounds, we could have a situation where it can deal with both cased and caseless rounds. Might be that some, like the Inferno rounds, for example, are caseless while the standard round is cased.

The way the bolter fires as I see it, is roughly akin to the Javelin Anti-tank missile launcher, in that an electrical ignition fires a small charge, shoving the round down the barrel and separating it from the case, as well as cycling the action etc. When the round leaves the barrel the main rocket motors fire and it shoots off to it's target.
Now that I really think about it, an electrical ignition system looks more and more likely.
Title: Re: Size of a bolter?
Post by: Sayt on July 1, 2009, 07:03:30 AM
 I stand corrected (http://wh40k.lexicanum.com/wiki/Bolt_Weapon#Bolt_Ammunition), they do indeed use cased ammunition.  Could have sworn the used caseless, and that the pics were just the artists assuming cased ammo.  Ah well.
Title: Re: Size of a bolter?
Post by: dragonclaw15 on July 1, 2009, 01:44:22 PM
Also, Space Marine Marksman Honor medals are gold-plated bolter shell casings.
Title: Re: Size of a bolter?
Post by: Wyddr on July 1, 2009, 02:52:39 PM
There isn't a particularly good reason why bolters *wouldn't* use a percussion-cap system, really. It has to be easier to accomplish than electrical ignition, for one thing. It makes the weapon need less maintenence, for another. About the only drawback might be that it would have difficulty firing in a vacuum, but that's probably pretty easily solved by sealing the firing chamber and pumping in just a bit of oxygen (requiring a bit of a refit, but nothing major).

I have always understood the bolt rounds as having two stages, if you will. First off is the conventional casing/explosive that propels the bolt out of the barrel of the gun. This is probably pretty small--just enough to chuck the thing a few yards/meters, after which point the jet on the bolt itself kicks in. This probably would be done to reduce blow-back from the jet's exhaust doing things like needlessly heating up the barrel, igniting other ammunition, or even to make firing in squad formations a bit less complicated (nothing worse than having your shoulder singed off because the guy behind you fired a bolt too close).
Title: Re: Size of a bolter?
Post by: Fugitive on July 1, 2009, 05:47:49 PM
I'm pretty sure there are no official measurements of the bolter. If you are thinking of building a full size replica I would suggest just estimating the size based on miniatures/art.

I have always understood the bolt rounds as having two stages, if you will. First off is the conventional casing/explosive that propels the bolt out of the barrel of the gun. This is probably pretty small--just enough to chuck the thing a few yards/meters, after which point the jet on the bolt itself kicks in. This probably would be done to reduce blow-back from the jet's exhaust doing things like needlessly heating up the barrel, igniting other ammunition, or even to make firing in squad formations a bit less complicated (nothing worse than having your shoulder singed off because the guy behind you fired a bolt too close).

Yes, I've heard that too. I always figured that was a compromise of sorts. Since the bolter was originally described as being caseless, but later depicted as using "cased" ammunition in gw art and fiction. I don't know if it's official tough. Another compromise could be big imperium = many kinds of bolters.


Title: Re: Size of a bolter?
Post by: Librarian Nikol on July 1, 2009, 07:06:57 PM
imperium = many kinds of bolters.

Very true. A quick list from our friends over at the Lexicanum:

    * Ultima Pattern
    * Crusade Pattern
    * Heresy Pattern
    * Filienostos Pattern
    * Nostra Pattern
    * Astartes Umbra Pattern
    * Godwyn Pattern
    * Godwyn-Deaz Pattern (used by the Sisters of Battle)

And I'm sure there are dozens of other, less-well-known variants made for the guard or PDFs as well as for the black market. These just are mass produced and not blessed by techpriests, simply stamped, forged and issued.
That raises another issue when talking about size. What pattern bolter are we talking about, for starters? I mean, I know we are talking about the Astartes MK Vb Godwyn pattern, the standard SMurf issue bolter, but we can't assume, for to assume makes and ass out of you and me.  ;)
Title: Re: Size of a bolter?
Post by: Lachdonin on July 1, 2009, 08:52:45 PM
There isn't a particularly good reason why bolters *wouldn't* use a percussion-cap system, really. It has to be easier to accomplish than electrical ignition, for one thing. It makes the weapon need less maintenence, for another. About the only drawback might be that it would have difficulty firing in a vacuum, but that's probably pretty easily solved by sealing the firing chamber and pumping in just a bit of oxygen (requiring a bit of a refit, but nothing major).

Actually, electrical firing system are not only easier to set up, but break down far less often because the only real moving part is the round. They also allow for a considerably greater rate of fire (For instance, the dual barrel Metal-Storm pistol can fire 3 rounds before the weapon actually recoils). Also, due to the fact they are still using hydrocarbon explosives, they are just as affected by low oxygen environments as a standard round.


Still we are talking about the Imperium here. It is possible, and indeed likely, that various Bolter Patterns use different firing systems.
Title: Re: Size of a bolter?
Post by: Shaviv on July 2, 2009, 09:03:22 PM
Notwithstanding the cased/caseless debate, everyone agrees that bolt shells are in effect miniature rockets. To that end, it would make sense if bolters are smoothbore (since the shells would stabilize themselves, by spinning or with fins, whatever). Also, then accuracy would not be affected by barrel length, which also explains why in old art or models you see bolters with the clips practically at the end of the barrel.
You could have saboted shells and use rifling, though, if you wanted. It would get a little ridiculous, perhaps -

I believe that British and French tank guns are rifles, even though the effectiveness of HEAT and APFSDS shells is reduced by rotation. So instead of the whole shell rotating, there's just a sleeve that engages the rifling. The sleeve spins freely around the shell, and it's heavy enough to keep the shell from tumbling. I think the APFSDS rotating collar breaks away as it exits the barrel, but don't quote me on that.

But with all this complexity, the reliability of the bolter - for which it is famed - would surely drop.

So I'm sticking with imagining it as a cased 12-ga or so round, in a straight, non-necked cartridge that has a relatively small charge. Short and stubby cartridges. Like that 20mm grenade launcher from the now-defunct OICW "let's make guns awesome" project.
Title: Re: Size of a bolter?
Post by: Ghostofman on July 2, 2009, 10:33:58 PM
And a bolter would probably be similar size to the OICW for that reason, maybe a tad larger. Most images seem to show bolters to be about the length of modern assault carbine, just bulkier. Remember that Space Marines are bigger then normal humans, but that aren't that much bigger, they might be more comfortable using an over sized grip and no trigger guard, but otherwise they wouldn't need further modification.

A lot of the pseudoscience fluff and flavor text fluff about bolters don't really match up. A micro rocket launcher would probably have a relatively low recoil (since the round would get lots of it's momentum from the rocket, it would only need the initial charge to be enough to kick it clear of the barrel, the lack of a stock on most patterns of bolter, both for SMs and normal humans, support this) but there are plenty out there that insist that a bolters recoil can dislocate or remove a limb (I guess because they just can handle the idea that something powerful would also be easy to use).

Title: Re: Size of a bolter?
Post by: Lachdonin on July 2, 2009, 10:54:50 PM
I tend to agree. The bolter is really little more than a launching platform for self propelled rounds. The kick on a standard bolter would likely be no different than a autogun or similar solid round weapon.

However, this all depends on exactly when the actual propellant kicks in. If it goes off before the bolt leaves the barrel (This seems unlikely, as there wouldn't really be a need for an initial charge then) then the blow back could be sizable. Most rocket launchers have considerable kick, and if someone tried to fire one from the hip, it would likely break limbs. If Bolters work in a similar way, i can understand how people can see them as being so over bearing.
Title: Re: Size of a bolter?
Post by: Koval, Master Verispex on July 3, 2009, 03:04:39 AM
They're described as having a fair amount of recoil, which leads me to believe that the bolter shell is fired normally and then the propellant activates about half a second later once it's clear of the barrel.
Title: Re: Size of a bolter?
Post by: Librarian Nikol on July 3, 2009, 05:29:45 AM
It could be that the smaller, simpler Guard bolters actually fire under a different principle, or have cheaper/less powerful rocket motors necessitating a larger initial charge to force it out of the barrel at a decent velocity.
Or it could be as far as to say that guard bolters act as normal, conventional firearms do and are fully cased gunpowder rounds that are fired wholly by the initial charge. That would explain it kicking like a mule, would probably be easier and cheaper to produce in large numbers, and would be the only kinds of bolters a normal human (besides SoB) would ever handle.
Title: Re: Size of a bolter?
Post by: Sir_Godspeed on July 3, 2009, 05:40:48 PM
I saw someone mentioning bolters working similarly to gyrojets back there (just... y'know, effective) and while I agree with that, you should know that last time I brought that up... well, suffice to say that there are people here who are violently against the idea. Don't ask me why.

- And aren't bolters renowned for their high-maintenance and complexity and not opposite?
Title: Re: Size of a bolter?
Post by: Koval, Master Verispex on July 4, 2009, 02:26:24 AM
I saw someone mentioning bolters working similarly to gyrojets back there (just... y'know, effective) and while I agree with that, you should know that last time I brought that up... well, suffice to say that there are people here who are violently against the idea. Don't ask me why.
Mostly because Gyrojets, as they stand, are terrible? According to wiki you can stop a Gyrojet by putting a piece of cardboard over the barrel -- try that with a bolter and it's like trying to stop a gale-force wind with a rolled-up newspaper.

The similarities are there, admittedly, but at the same time it's a chalk-and-cheese comparison.
Title: Re: Size of a bolter?
Post by: Lachdonin on July 4, 2009, 05:24:54 PM
I'd argue its more of a Musket - AA12 comparison.

Gyrojet are essentially the same weapon, just far less sophisticated.

Chalk and Cheese are two completely different things, where as the Gyrojet is the great great great (and so on) grand-daddy of the Bolter.
Title: Re: Size of a bolter?
Post by: Shaviv on July 5, 2009, 12:25:50 AM
I saw someone mentioning bolters working similarly to gyrojets back there (just... y'know, effective) and while I agree with that, you should know that last time I brought that up... well, suffice to say that there are people here who are violently against the idea. Don't ask me why.
Mostly because Gyrojets, as they stand, are terrible? According to wiki you can stop a Gyrojet by putting a piece of cardboard over the barrel -- try that with a bolter and it's like trying to stop a gale-force wind with a rolled-up newspaper.

The similarities are there, admittedly, but at the same time it's a chalk-and-cheese comparison.
The gyrojet's low muzzle velocity could probably be improved, though, by putting the round into a cartridge, and behind the motor have a normal powder charge for, let's say, a 10mm handgun round, and in between thepowder charge and the motor, have a tamper of some sort to reduce the chances of theinitial blast damaging the delicately machined nozzles.
Title: Re: Size of a bolter?
Post by: Sir_Godspeed on July 5, 2009, 09:09:26 AM
My point is simply that the gyrojet and the bolter are both based on the same principle; repeated firing of self-propelled rounds from a hand-held weapon. That's it.

Moving on, sorry if I created a digression.
Title: Re: Size of a bolter?
Post by: Lachdonin on July 18, 2009, 01:23:46 AM
Been awhile, but i had a touch of epiphany while looking around on Forge World's site. I came across a re-release of the old Space Marine piece, and they had the original advertising picture there. The stance shows the Marine reloading the bolter, and it shows clearly the actual cartridge breach. Low and behold, while only half paying attention, i noticed something. The rounds are placed in two columns.

A dual feed would account for the claims that the Bolter Clips hold 20-30 rounds without making them absurdly long. They would almost certainly have to be slightly broader than they are on the model, but its an answer to one mystery. How the rounds would feed without causing the weapon to jam is another matter, but its 35,000 years in the future, i feel we can assume they've found a solution.
Title: Re: Size of a bolter?
Post by: Cpt. Pain on July 24, 2009, 06:07:54 PM
Double column magazines are nothing special, the Thompson SMG had such a system...
Title: Re: Size of a bolter?
Post by: Lachdonin on July 24, 2009, 07:44:29 PM
It's also terribly unreliable and jams often. Regardless, i brought it up as it gives an explanation for how a Bolter can have a 30 round clip without it being over half meter long.
Title: Re: Size of a bolter?
Post by: Cpt. Pain on July 24, 2009, 07:58:39 PM
Actually, its not 'terribly unreliable and jams a lot'. While zigzag stacked magzines do jam slightly more than single column magazines, they are really very good. Infact, the thompson, and its 20/30 round box magazines were highly regarded for their reliablity, more so that the staggered, single feed that the Sten and Mp40 used (which have to blend the two columns into one at the top). ALL modern assault rifles use them. A 7.62mm has a cartridge width of about half a inch, maybe more, a an associated 30 box magazine is nowhere near 50cm.

While it WAS a good idea, it was my no means the first time it was thought of  ;).
Title: Re: Size of a bolter?
Post by: High Grandmaster smithmyster666 of the Grey Knights on July 25, 2009, 02:15:14 PM
a bolter round id imagine is a similar size to the 35mm aircraft minigun round used nowadays just different in projectile shape and assembly of the round itself. anyone who hasnt seen the size of them theyre like miniature tank shells in size. so they would easily would have a magazine width of around 25cm when you add up the size of the casing for the mag and such on. you cant expect them to have flimsy 2mm steel as a casing so around 8mm of metallic substance is appropriate.
Title: Re: Size of a bolter?
Post by: Koval, Master Verispex on July 27, 2009, 03:32:32 PM
Quote
a bolter round id imagine is a similar size to the 35mm aircraft minigun round used nowadays
that's far too large, bolter shells are established to be .75 caliber which is about half that.
Title: Re: Size of a bolter?
Post by: Sir_Godspeed on July 27, 2009, 04:27:28 PM
As for the "nah, that wouldn't work cuz it's hard to make"-argument I see pop up here every once in a while; it's 38,000 years in the future. They might just have solved some issues.

Also, the bolters are commonly referred to as being high-tech as well as reliable (and arguably high-maintenance. A possible contradiction, or?)
Title: Re: Size of a bolter?
Post by: Cpt. Pain on July 27, 2009, 06:55:28 PM
Its not a contradiction, and the Nercomunda rules system agrees with you. Bolters (and to be honest, most military grade firearms in the game, excluding lasguns) are described as highly reliable when kept in condition by an armourer with the right tools. When used by the layperson, the frequency of jamming rises rapidly with useage.
Title: Re: Size of a bolter?
Post by: Semaj_14 on August 22, 2009, 06:07:16 AM
On the Cased not cased ruling. I do remember reading somewhere that bolters took Caseless amunition. It may have been in one of the Index Astartes but I am probably remembering something else. Although The only reason I remember that Is because I turned around and looked up what the heck it meant by caseless ammunition.
And remember these are supposed to be 8-10 foot tall warriors. those bolters are gonna be mighty mighty. I find that people who play the table top and are constantly seeing Marines that are barely taller than Guardsmen Forget that from time to time.
Title: Re: Size of a bolter?
Post by: Irandrura on August 22, 2009, 09:51:55 PM
Let sleeping topics lie. There was no need to bring back a topic three weeks old. In future, please be careful to check the date of the last post. This board moves more slowly than many others, so be especially on your guard here.