The future of Small Arms and the reliability of New Technology

[Minuteman37]

Originally Posted by Anthony

While you're not going to manage a rocket on the same propellant mass as a gun, managing a rocket for no more mass than propellant+case is probably doable.

For current cased ammunition yes, but as rockets are developing so are conventional and casesless ammunition. The later is substantally ligher and the former is under heavy pressure to develop a lighter body.

That coupled with the issues you present lead me to believe it will be a long time before gyros ever see combat.

[warellis]

Originally Posted by Minuteman37

For current cased ammunition yes, but as rockets are developing so are conventional and casesless ammunition. The later is substantally ligher and the former is under heavy pressure to develop a lighter body.

That coupled with the issues you present lead me to believe it will be a long time before gyros ever see combat.

We sort of have gyros right now it looks like:
http://www.thefirearmblog.com/blog/2...-2-kilometers/

[lwcamp]

Originally Posted by Minuteman37

Look, for any of these technologies to become viable hand held weapons we'll need advances in heat distribution, so I'm kind of ignoring it at the moment.

Modern laser weapons and high power machining lasers typically run at about 30% electricity-to-light efficiency, with some examples demonstrated at 50% efficiency.

A modern firearm is typically about 20 to 30% efficient at turning the chemical energy of its powder into kinetic energy.with about another 30% to 40% of its energy going into heating the weapon.

By my best estimates, a pulsed laser could deliver a similar level of wounding (and significantly higher armor penetration) as a bullet with about the same amount of energy.

Combine these, add in advances from rapidly improving laser technology, and you can see that a laser will generate a similar or lower heat load compared to a firearm, with consequently similar or lower difficulty in heat rejection. Notably, modern fiber lasers are well known for being able to tolerate high heat levels and keep working without degradation in beam quality.

Luke

[lwcamp]

Originally Posted by ericbsmith

Properly cleaned occasionally that shouldn't happen. OTOH, some computers (like laptops) are difficult to clean. Which is one of the issues that weapons grade Lasers would face - you need to keep the electronics clean while also keeping them cool. Those are two opposing goals; you can set up heatsinks to get heat out of sealed electronics, but unless you use a fan or water tank to cool the heatsink things can still get toasty. This is not insurmountable, but it does add complexity.

Advanced materials will help. Both diamond and graphene have anomalously high thermal conductivities (a natural consequence of being made from light atoms with stiff chemical bonds). We can't make either of them in bulk right now, but I expect that will change. A monolithic heat sink with no moving parts would help.

You can also include heat pumps, some of which have been designed without moving parts (like those that work with sound waves). The no moving parts varieties are not cost efficient with the usual method of pumping liquids around in pipes, but they have been demonstrated.

Luke

[lwcamp]

Originally Posted by Tinman

Of course, there is also the issues of effectiveness.

While lasers seam sexy & cool, I doub't their ultimate effectiveness as infantry weapons. Bad weather, smoke, dust, ect... will interfere with their delivering enough power to effectively harm an armored soldier.

I believe that kinetic energy projectiles (gauss or conventional) will be the future of infantry/ground combat.

If you can see them, it means that light can get from them to you and vice versa. So your laser can hit them. If you can't see them, what are you shooting at?

Luke

[lwcamp]

Originally Posted by AlexanderHowl

You really cannot clean the lens of high energy lasers with anything other than sprays of liquid nitrogen (researchers avoid the issue by having clean room protocols when accessing the lasing medium). Even silk would scratch the lens enough to cause catastrophic failure for the high energy laser. The last thing you would want is any drop in laser efficiency because the resulting waste heat will destroy the laser.

There are scratch resistant coatings, you know. Diamond, silicon carbide, cubic boron nitride - all very hard, high refractive index, extremely refractory, high to extreme thermal conductivity, ideal for coating or making lenses. And now they are coming up with self-cleaning coatings that are transparent, and could be made out of that self-same diamond, silicon carbide, cubic boron nitride, etc, by adding microscale patterns to the surface.

Luke

[lwcamp]

Originally Posted by apoc527

The only question I (repeatedly) have about ETC firearms is exactly what their performance will look like in comparison to modern propellants.

Has anyone taken a super hard look at this? Maybe Luke Campbell or gurb3d6?

You could get slight increases in muzzle velocity and muzzle energy. You are still limited by the finite speed of sound of the propellant gases, which gives you an upper limit on your projectile speed. My best guess is that what GURPS describes as ETC will be just a little bit better than modern smokeless powder firearms.

Luke

[lwcamp]

Originally Posted by weby

Yes, throwing a slug is more efficient in terms of delivering energy to a target and less affected by things. So I definitely agree that such is much more likely as military weapon.

When I looked into the energy necessary to put holes in people with beams of light, I found that with pulsed beams you could get roughly the same level of penetrating into meat compared to a bullet with about the same amount of energy. This would require at least MW beams, probably delivered in about a microsecond. If you could deliver a train of nanosecond pulses each with about ten or so joules it could work even better. At the extreme limit you have monsters like the NIF lasers, that produce similar levels of destruction as a stick of dynamite with each shot, delivered with the same amount of energy.

Now my estimates were made using theory and calculations, because we just don't have experience with MW beams impinging on flesh and bone. So there's always room to question them. My calculator works okay when comparing to known examples - better than an order of magnitude agreement in any case - ranging from industrial drilling lasers to cratering from asteroid impacts, nanosecond laser pulses, and nuclear detonations. But the effect of what seems ideal for a laser weapon is not in the parameter space of cases that have data I could find.

Luke

[lwcamp]

Originally Posted by Ji ji

Yes. The present problems of EM or laser weapon could be overcome in little time, or never - there’s no way to make a reliable prediction.
Caseless ammo have their still unsolved problems.
Liquid fuel ammo and rocket ammo are interesting, too. Why underestimate rockets? They have the potential to solve the main problem of all small arms but lasers, that is recoil; they are simple, rugged and reliable. They have huge room for futuristic tricks like homing payload bullets full of unobtanium and ****.

Ok, now I am convinced that rocket small arms are the way to go.

Rockets also have the advantage of looking like Star Wars blasters - a streak of light shooting toward the target from the exhaust flare, and an explosion once it hits.

Luke

[warellis]

Originally Posted by lwcamp

Rockets also have the advantage of looking like Star Wars blasters - a streak of light shooting toward the target from the exhaust flare, and an explosion once it hits.

Luke

That's a disadvantage and the ones you guys are suggesting are probably too small to not be worth it. Unless they're good for airbursting troops behind cover or something, getting smaller than 25mm is probably not worth it.

They're also heavy and troops today are already far too overloaded from the weight of armor and equipment they have to use. In current COIN ops, US troops are carrying around 55% of their bodyweight in gear and weapons.

And it weight goes up against peer opponents.