This is the closest to a bolter I've seen so far. (especially when you get to using the frag-12 rounds) Combine this with gyrojet technology and you're almost there:

I love this gun. I want one right now. I don't think there's a semi-auto civilian model available currently. I'd love to hear otherwise. I wants it. I neeeeeds it...I want to bring this baby out to the ***** range and make some serious noise....for the emperor, I mean.

The "bolter" is, of course, going to be the next step in the evolution of the combat rifle. The only way to substantially improve on current designs is to add self-propelled, explosive rounds. We will see its like in the very near future. Ammo will be heavy and expensive, and very effective -even against armour.

What's the point in making it self-propelled? It's not like bullets are slouches in the speed department. Plus, we've had gyrojets for 45 years. We don't use them because they suck.

I'm cool with just the fin stabilized frag-12 rounds. But to meet 40k background info on bolters you need to add an armor piercing tip and self-propelled. Even it it doesn't match the sci-fi the real thing is pretty **** cool on its own (and almost recoilless!)

bogi_khaosa said:

Yeah, they suck. They suck because they have extremely low muzle velocity. If I shot at you with a gyrojet pistol at really close range the gyrojet rocket would probably just bounce of your skin.

On the other hand, gyrojet projectiles could reach very high velocities once they had the time to pick up sufficient speed. Just imagine the range you could get if you designed it like a two stage rocket where you have a primary charge (like gunpowder) that flings the rocket out of the muzzle at the same speed as a conventional bullet, but instead of declining in velocity once the bullet leaves the muzzle the miniature rocket engine kicks in and let's the bullet fly even further.

They never tried that design with the gyrojet, they hoped that the rocket engine would be enough.

You have to make it a Gyroget because a Bolt Shell is .75 Calibre so the recoil would be immense. A gyroget has a low initial speed and so a low initial Kinetic Energy which is why its needed in a bolt shell.

Kaihlik

A 12 gauge shotgun is pretty close to .75 caliber (.729 to be exact)

That's why I said all a frag-12 shell needs to be a bolt shell is to add a rocket booster and an armor piercing tip.

Kaihlik said:

Except that bolt shells are two-stage - they use a primary propellant charge to fire the shell from the weapon (accelerating it to a decent velocity), and then the rocket motor kicks in a fraction of a second afterwards.

Bolters do have considerable recoil (greater than calibre alone might suggest, due to high-density components like the DU armour-piercing tip) - that's one of their defining qualities.

N0-1_H3r3 said:

Yup. But still the recoil is bearable. Mainly due to their bulky design. The heavier the weapon is, the more recoil gravity will absorb. Also, I think bolters meant for humans use an open-bolt mechanism for reloading, that would also significantly reduce the recoil to bearable levels, although accuracy would be slightly reduced.

bogi_khaosa said:

Well, there are a few reasons to make the round self-propelled. For starters, putting a high-explosive charge through the sort of compression that a supersonic round withstands puts a limit on the grade of explosive and primer you can use. Using a relatively low initial muzzle velocity created by a standard powder, and a steady acceleration takes care of this problem. Its like an M203 round that continues to accelerate steadily after leaving the barrel.

Secondly, extremely large caliber rounds are much easier to fire at low velocities. If a shotgun fired pellets at supersonic speeds, the weapon wouldhave to be massive just to contend with the recoil, and even then would probably be untenable as a small arm.

Thirdly, if a round were self-propelled, there would be little need for a long barrel or for rifling. The round would not have to be spun up to full speed by the barell, it could actually provide its own angular momentum. So a weapon could be more powerful, more accurate and have a short barrel.

Fourthly, truly phenomenal speeds could be reached with a round than continues to accelerate without gas pressure. This frees the weapon system from any upward limits on chamber pressure or stresses suffered by the round upon firing. You could achieve armour-defeating speeds even. This, plus an explosive charge, makes an infantry small arm that can contend with tactical vehicles....Or space monsters!

All in all, the only downside would be the cost and sophistication of the rounds.

Nullius said:

Of course, if you're dealing with an Astartes bolter, which is known to be significantly larger and heavier (partially because they're armour plated to withstand the same sort of brutal attention that the weapon's owner will receive) and wielded by warriors more than strong enough to handle what might otherwise be bone-breaking recoil (and each of which is hand-machined from the finest materials to extremely precise tolerances), you can have a weapon that fires a large calibre shell of that kind at much higher initial velocities...

Nullius said:

Which explains why bolters tend to look quite short and stubby, without much of a barrel to speak of. Take the bolt pistol for instance, look at where the magazine is located and to which part of the gun the ammunition is fed. The round doesn't have that much of a barrel to travel through, but since the rounds are self propelled that won't be an issue.

Lets be honest, the future of assault weapons isn't solid projectiles, it's laser weapons and true lasers, not the 40k sissy lasguns. The penetration and accuracy of a laser will far exceed any solid projectile. Even then if you want truely devestating solid projectile, magnetic acceleration not propellants is where you go.

http://en.wikipedia.org/wiki/railgun

Just read the math and physics of it a 2kg (4.4 pound) heavy metal slug could shoot through a tank.

True at the moment the weapon systems are about as long as a football field, but given time as with everything they will shrink in size.

The best part is that they have zero recoil.

I always wondered if the reason Space Marines use bolters is because genuinely self propelled projectiles would be a logical way to allow the Space Marines to fight in...er...space.

Now it's often been said that my knowledge of the laws of thermodynamics are shaky (my background is in sympathetic magic and jewel theft, not hard science) but isn't it the case that if an astronaut in a "zero-G" microgravity environment were to fire a .75 calibre conventional firearm in space, he'd end up flying backwards and spinning uncontrollably? Forever?

If the boltgun fires in effect mini rockets, I would have thought this might alleviate this issue. Of course, Marines are conventionally seen firing bolters as if they kick like a mule, so I could be wrong...unless the bolters have a special "space" setting that doesn't involve any conventional firearm-style propellant, just the bolt's own propellant.

Anyway, just a thought, as I say, my grasp of zero-G physics is pretty poor!

Lightbringer said:

Well, remember that p= mv or momentum equals massXvelocity. The mass of the bolt-round would be relatively small compared to the mass of the bolter+ the Space Marine. Now, I'm not entirely sure how much a space marine is supposed to weigh, nor am I sure how much a bolt-round is supposed to weigh, so I'm going to make up some numbers, then we'll do the math...

Now, a twelve-guage shotgun shell weighs about 40 grams. Lets guesstimate that a bolt shell weighs about three times that, so 120 grams. Lets, furthermore postulate that the initiall muzzle velocity of the round is something in the area of a shotgun muzzle velocity. A brand name slug is advertised at around 1760 feet per second, or 536 meters per second.

Now, at the risk of sending dork-temperatures rising, lets postulate the weight of a space marine. The tallest man on record was around eight feet eleven and 240 kilograms. This is a bit tall for a space marine, but marines are probably signifiganyly more muscular and bony. Perhaps being as much as 50% more massive, so 360 kilograms. Lets add the wight of a bolter, an for the sake of argument, lets make it about the weight of an M2 50 cal, so about 60 pounds, then lets double that and go metric for about 45 kilos.

The weight of the armour is anyone's guess, but its probably quite a bit heavier than the marine wearing it, perhaps somewhere in the range of 1000 pounds (just for the sake of argument. ). That's another 450 kilos more or less. That leaves our rough space marine with bolter mass at a rough 850 kilograms, + odds and ends so: 900 kilograms...

p+mxV

MxV=MxV

900000grams( X ) = 120(520m/s)

(X) = .07 meters per second.

So, given this set of made up numbers, each round fired would send the poor marine flying the other way at about .07 meters per second. In a complete vaccum and zero-G, the would add up as mrounds are fired. All this could be mitigated by lowering the initial muzzle velocity. to say : 100 meters per second, which would give us a value of about 1 centemeter per second per round. By setting an even lower initial muzzle velocity, this problem could be almost completely eliminated.

So, the 'self-propelled' concept would pretty handily solve this particular recoil problem too.

I think it's been agreed a bolter likely has a conventional primer/propellant base that accelerates the round out of the barrel which is then further accelerated by some means of self-propellant. So the weapon has recoil, significant recoil. As a solid projectile it's unlikely the muzzle velocity is as low as a shotgun shell.

I also think you're heavily overestimating the weight of their armor. At half a ton it's tacticly unsound to have something that massive, you severally limit mobility simply by the fact that you couldn't move over certain types of terrain or through certain buildings without causing structural damage and collapse. I would say their armor likely weighs closer to half of a space marines weight.

As for firing such a weapon in space, pretty easily done. The math is correct and even with a lower overall mass of the firer his relative acceleration due to weapon discharge would be minimal and something easily countered with a thruster timed to the weapon firing.

Gabriel said:

Not necessarily. We still don't know if it's physically possible to build a small and compact enough powersource to actually produce a portable laser assault weapon or railgun.

Technology has taken quite a few leaps over the last hundred years, but still mankind sucks at storing vast amounts of electrical energy (that's why we don't prefer to drive around in electric cars, because you'd have to recharge them way to often).

Of course, some sort of breakthrough might occur, but it could well be against the laws of physics to store the needed amount of energy in a device that's small enough to be portable and combat effective. (meaning that while the lasgun might be a piece of sci-fi tech, it is truly the CHARGEPACKS that are the most sci-fi part of the gun in general )

Railguns on the other hand do need significantly less energy to be combat effective, however the same thing might apply to them. Sure we might see them mounted on battleships and other large warmachines with their own internal powerplants, but we can't predict if it will be feasible for it to ever become compact enough to be portable.

Solid projectile weapons however can still be improved upon in many ways. One major improvement recently made is the significant reduced recoil in the KRISS .45 SMG. Take a look!

There' also the Metal Storm firing method:

www.youtube.com/watch

These are only a few examples of course, but it shows that good old fashioned solid projectile weaponry will stick with humanity for quite a few years to come. All avenues with them haven't been explored yet. Laser rifles and rail rifles on the other hand will at best be seen mounted on vehicles capable of producing the adequate amount of energy for them, and won't likely be seen in the hands of a normal infantry trooper.

Of course, it also depends on how project landwarrior is coming along (project landwarrior is basically the pursuit of building power armoured exo-skeletons). Who knows? These might be able to include some sort of portable powerplant (porable for them that is, not an unarmoured human being), and they might be sporting railguns and laser rifles. Although when you're basically a walking tank one would wonder why you'd need recoilless weapons in the first place, when you could pretty much lug around two .50 cal machine guns and fire them both on full auto and still keep your aim steady. But then again, if you could make a landwarrior portable railgun then it might just pack more punch than the .50 cal machineguns.

As for bolters. I don't know, I think the idea would be hard to sell. It would remind potential investors too much of the gyrojet concept and that pretty much failed miserably. But on the other hand, it would be one nasty (if extremely expensive) bullet, and with some proper engineering it might just outclass conventional bullets when it comes to range and stopping power.

Gabriel said:

Well, that is the muzzle velocity for a solid projectile. That's a 12-gauge slug, not buckshot. Its a perfectly acceptable kill velocity. With the right kind of round you can kill a small bear, particularly if you empty the magazine. And if you tripled the mass, you'd be talking about a seriously dangerous projectile, even at such a low muzzle velocity. The rest of the numbers are way overestimated, including the mass of the bolt shell. It was merely for demonstration's sake. As for the mass of the armour, its hard to say. Afterfall, how much does ceremite weigh? Modern cermaic armor is very heavy, and a suit that size could easily wiegh 1000 pounds. The side door of an up-armoured humvee weighs 800 pounds (although that's carbon steel), and that's a lot smaller than a space marine. Even a very small aluminum engine block for an automobile averages a couple hundred pounds, and the power plant on power armour is signifigantly more powerful (and larger, and you can't build a rector out of all composites). Batteries are also murderously heavy, no matter how advanced they are. And then you would have all of the motive components of the armour, which would probably be a few hundred pounds more(at least as much steel as an automobile frame. All things considered, I lowballed an estimate at 1000 pounds. I think the Master Chief from Halo weighs about 2000 pounds. That's probably a little more realistic.

Don't forget, the advantage of powered armor is that it carries its own weight. Even a tactical marine is basically a walking tank (as my poor Imperial guard army so often discovers)....

Oh well. Its all imaginary, in any event. I guess we'll see the first power armour in our lifetimes, and it could turn out to be very light indeed...

Nullius said:

I know I will. A friend of mine is designing and making a suit of it for the final year project of his cybernetics degree.

true the bolter is described as being a self-propelled, armor-piercing, explosively-tipped round.

now, there are a lot of ideas how this would work.

first off, the weapon: i'm thinking it would have to be "chain fed", meaning that the bolt and carrier mechanisms of the weapon are operated, basically, by a bike chain that would serve a multitude of advantages;1) would make feeding of the supposed "recoilless" round possible.2)improve reliability by automating the mechanism (ensuring that dud rounds were ejected and not causing a malfunction).... also this would add problems such as increased size and weight, also complications of maintanence....

now, the round: the round would consist of the case and projectile, the case would be a necessity to ensure that round cleared the muzzle and therefore, allowing the rocket motors to engage at a safe distance (engaging in the chamber of the weapons brings in the problem of heat build-up which might cause other issues, such as, maybe, detonating the magazine.....) also the case would need to serve the purpose of "arming" the fired projectile.

and finally, the projectile: this would need to be fairly heavyin order to hold both explosive charge and rocket propellant. the size of the explosive charge could be cut down by incorporating a "shaped-charge" or "explosively-formed projectile" warhead which would still be effective even against body armor or in the latter case, light-medium armored vehicles. the propellant would need to be solid and the ejection nozzles would need to be oriented to provide stable even twist along a given flight path. the round would also need to be fin-stabiled for added lift and stability and would act as a slight corrective force to turbulent weather.

...to get an idea go to wikipedia and look up the "gyrojet","shaped-charge warheads" and anything else that is unfamiliar to you...

Signed,

Temple of the Cult Mechanicus, Mars......

tell your freind to look into something called "ballistic foam" it should help decrease a lot of the weight....

Gabriel said:

Nah... Maintenance, field wear, power requirements, and a host of other issues will make energy based infantry weaponry unfeasible for a long, long time.

Right now railguns by their nature generate immense amounts of heat and wear along the rails due to friction. The solution is a coil gun or something similar, but again, you're dealing with huge amounts of power, and a gun that can't take soaking in the mud for a week at a time.

Go look at Metal Storm on youtube. That's the future of our weaponry right there. Over 1 MILLION rounds a minute, solid state, no jamming, caseless ammunition, with selectable ammo types based on barrel used. All powered by something like a AA battery. They say that you can have something like 70 rounds of ammunition in 4 barrels on a metal storm pistol, and changing out the barrel assembly takes about as long as changing a normal magazine these days.

Remember, stopping power and accuracy is nice, but reliability, resistance to field wear, and expense also plays major factors in military weaponry. It's what made us jump from carbine and full battle rifles to sub-machine guns and assault rifles.

TheFlatline said:

Exactly. There's a reason combat rifles haven't substantially changed since the korean war. Lots of research has been done on the subject, but projectile weapons are cheap, easy to manufacture, durable, and field operable. A Laser weapon would have to bring new capabilities to the battlefield in order to justify its deployment. Likewise with magnetic weapons. That an energy weapon could potentially do the same job as a combat rifle isn't reason enough for it to be deployed as a small arm. It would have to do the job signifigantly better or cheaper. Given that the job of a combat rifle is to kill poeple -a duty it is admirably capable of, thankyou very much- it is hard to imagine laser weapons doing this better or cheaper, unless the cost of energy and hi-tech batteries comes down a lot...

Of course futuristic combat armour could always change the rules of the game.

Since i'm neither an expert for firearms or weapon developement consider my statement as the one of the usual 'civilian':

Just looking back at what kind of batteries and electronics we had back in the 80s, and which we have now i do dare to say that a laser rifle is not soooo far away from seeing a laserrifle in the future (less than 50 years).

Since no material is unlimited on our little planet, unlike energy thanks to outside sources, at one point 'batteries' will be cheaper to build and recharge than bullets. I do not know how much is true about what i have heard about those liquid core batteries which are tested/developed, but they seem to be very close to how the charge packs are described in the IG Codizes.

But i'm quite eager to listen to what real experts about that can tell us. So, if you know more than me, spit it out. ^^

segara82 said:

Okay. Something like a lasgun would have to have an energy output in the megawatt range. Maybe only one megawatt. That's 1000 kilowatts. Right now, a battery the size of a fridge can store 20 kilowatts. So 50 fridge sized batteries that weigh several hundred pounds each would generate one megawatt laser shot. And those liquid core batteries don't output all that power at once. The prototype outputs that energy over 4 hours or so. Most deep-storage batteries with high density don't output all at once, which you'd need to be a practical weapon. Having even a 3-5 second recharge time between shots while a capacitor fills up is simply not practical compared to a solid state projectile. We simply do not know how to store massive amounts of suddenly-releasable power in the megawatt range and do it in something that is roughly the size of a man's fist aside from capacitors, which carry their own issues.

Basically, we're several orders of magnitude away in both weight and size, and let's say one or two orders of magnitude away on storage. We haven't come *that* far in 30 years as far as batteries are concerned.

On top of that, laser effective range is generally considered to be a non-constant. Lasers will encounter temperature and humidity changes during it's flight, which will cause diffusion. Over long ranges (say half a mile for a long las?) right now the Air Force is unsure if performance would be steady enough to make worth while. And that's a law of physics, not a technology hurdle that needs to be overcome.

It might be feasible some day, but right now there aren't even theories out there for how to solve those logistics. My guess is that if laser/energy based weapons are to be feasible, it won't be batteries that supply power, it will be small-scale generators providing power directly to an array of ultra-efficient capacitors, bypassing batteries (which the chemists have always lagged behind the physicists) entirely. With, say, 10 capacitors in an array, if it takes 2 seconds to charge a capacitor, you could sustain a higher rate of fire for longer.

Even then, if you could produce power that efficiently, say cold (or at least contained) fusion, then it'd probably be much deadlier to unleash that level of power as plasma than as a laser.