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So would lasguns, being energy weapons, have recoil?

I don't believe so, in a Ciaphis Cain novel, The Greater Good, it is mentioned an aquila had an autocannon, which is strange for such a ship as the recoil would require compensation from the thrusters, while most use las guns, which would imply they don't have a recoil, or its much less.

They're lasers so no. That would actually be a pretty big advantage over a solid shot weapon. You would also not have to lead targets you are aiming at and would have greatly increased range.

Thats what I would think, but In one of the GG novels it mentions the sniper adjusting for windage, which shouldn't be a problem with a laser beam. I guess its just creative license with the writers.

How about a plasma gun?

Strictly speaking, a laser weapon shouldn't have recoil. However, if the laser pulse is significantly powerful enough the super heating of the air in the barrel of the gun could cause some gas expansion. Thus resulting in recoil.

Alternately, lasguns actually are only using a laser to create a small plasma pulse(which would generate actual recoil) but it still looks like a laser gun. Hence the "lasgun" moniker. Plasma guns will have recoil for the same reason.

In either case, lasguns have usually been described as not having much recoil relative to regular guns.


And you'd still need to lead your targets. The laser might travel instantly for practical purposes, but the human reaction between the brain telling the finger to pull and the finger actually pulling will still result in lag.

Adjusting for windage would actually make sense in some situations, especially conditions which could lead to distortions of the beam. Different air densities along the path, any particles in the air, etc... It would have a totally different set of rules than doing the same for a bullet, but you could still result in distortions that would need to be adjusted. Light always doesn't travel in a straight path, it is effected by gravity and air/liquid densities like anything else.

Plasma guns are a made up weapon so it probably varies with whichever fluff tickles your fancy.

And you'd still need to lead your targets. The laser might travel instantly for practical purposes, but the human reaction between the brain telling the finger to pull and the finger actually pulling will still result in lag.

The amount would be incredibly small, and also muscle memory effectively bypasses this. How much you would need to lead would also not vary with distance. Your eyesight would be more of a burden than the lasgun.

Mustela wrote:
They're lasers so no..

Being a laser weapon doesn't inherently mean that it won't have recoil. Some of the (real-world) theoretical designs for gas-powered laser rifles wind up with considerable recoil due to rapid acceleration of the gas in the weapon.

Raven911 wrote:
Thats what I would think, but In one of the GG novels it mentions the sniper adjusting for windage, which shouldn't be a problem with a laser beam. I guess its just creative license with the writers.

Not sure which scene you're referring to specifically (and I know that there certainly is a sniper in the GG books who just uses an extended lasgun) but sniper rifles in 40K generally fire toxic darts - the 'traditional' needle sniper rifle fires a short las-burst to penetrate armour, and then follows it up with a toxic dart to actually make the kill ... so while the laser component might not be affected by wind, the dart certainly would be.

Larkin uses a "hot-shot" las, which (in GG) is a single-shot lasgun with greater range, armor penetration and stopping power than a standard lasgun.

Of course, depending on who you read, the actual effects of a hot-shot lasgun (or power cell) varies, but that's how Abnett describes it working.

Adjusting for windage with a laser weapon could be to do with avoiding dust blown into the line of fire by gusts of wind, with the worry that the dust would diffuse and scatter the laser.

Raven911 wrote:
So would lasguns, being energy weapons, have recoil?

depends on the power. Photos do have momentum.

So I did a little research. I guess a man name Larry Niven did some research into this wondering if lasers could be used as thrusters. He found that while lasers do produce recoil, even an insanely powerful laser wouldn't produce much. So maybe a lasgun would just give a little nuzzle while a lascannon would have some kick.

It wouldn't have any recoil, no gas is being expelled from the barrel. It's like turning on a light.

 Harriticus wrote:
It wouldn't have any recoil, no gas is being expelled from the barrel. It's like turning on a light.

Thats not necessarily true.

There will be gas in the barrel from the surrounding atmosphere, gas which will be heated quite significantly by the laser. That could produce some recoil.

Alternately, the gun itself could easily be gas cooled and it ejects the superheated gas on top of everything else. Of course if that were the case the smart designer would have it eject in a way which didn't move the gun much, but it is possible.

Plus as was mentioned before, some theoretical weaponized lasers would indeed have some recoil. Small amounts mind you, but still there.

Maybe the lasgun STC was for a toy model that simulates combustion firearms, with artificial recoil machinations built in. And in humanity's infinity savagery, every colony lost the military lasgun design and had to resort to convert ancient plastic toys into laser zappers...

They're lasers - means light. Light has recoil but it's much lower than one of a firearm.

Lasguns are basically big torches given to unsuspecting guardsmen.
Do torches have recoil?

Writers have a hard time determining whether lasguns fire bolts like Star wars blasters or beams like in dawn of war. DoW has pushed the scale towards the short lived beams though. Recoil is often shown for the sake of dramatic imagery rather than anything particularly sensible though.

They do both, depending on the pattern of lasweapon, of which there are literally thousands, if not millions, in the Imperium.

If you want your lasguns to be SW blasters, make them be "Pattern XYZ from Forge-World YaddaYadda". If you want them to fire beams? Make them "Pattern ABC from Forge-World YakkitySchmakkity". There's room in the setting for both, and everything in between.

 Psienesis wrote:
They do both, depending on the pattern of lasweapon, of which there are literally thousands, if not millions, in the Imperium.

If you want your lasguns to be SW blasters, make them be "Pattern XYZ from Forge-World YaddaYadda". If you want them to fire beams? Make them "Pattern ABC from Forge-World YakkitySchmakkity". There's room in the setting for both, and everything in between.

or they could be autoguns, which are functionally identical to lasguns.

Yeah, if you want an assault rifle firing lasers, go ahead. In-setting, though, an autogun is a solid-projectile weapon, rather than energy-weapon.

I think by 'functionally identical', Exergy meant that they have the same effect on the things they're shot at, in terms of penetration and damage.

Maybe, but the "or they could be autoguns" threw me off, because that implies that autoguns *are* laser-firing weapons.

Though, yes, the Guard of some backwater world might be armed with autoguns and not lasrifles, though Throne only knows why.

 Psienesis wrote:
Maybe, but the "or they could be autoguns" threw me off, because that implies that autoguns *are* laser-firing weapons.

Though, yes, the Guard of some backwater world might be armed with autoguns and not lasrifles, though Throne only knows why.

I'd imagine that autoguns are mostly a PDF and Frateris Militia thing when the troops are drawn from planets that cannot into laser technology.

Yeah, the Frateris Militia are usually armed with whatever tool was on hand when they walked off their jobs and went to war.... pitchforks, hammers, chisels, brooms, laser-cutters and plasma-torches.... just all the stuff available to a mob of hysterical zealots.

Frateris Militia generally end up armed with a mix of shotguns, knives, frying pans and stub pistols.

Psienesis wrote:Maybe, but the "or they could be autoguns" threw me off, because that implies that autoguns *are* laser-firing weapons.

Though, yes, the Guard of some backwater world might be armed with autoguns and not lasrifles, though Throne only knows why.

My Guard have autoguns because the models are armed with M16s with air-cooling-jackets on the barrels. ^^; The fluff is that Loxatl are fairly common in their region of space (Loxatl are lasproof, somehow).

 Psienesis wrote:
Yeah, the Frateris Militia are usually armed with whatever tool was on hand when they walked off their jobs and went to war.... pitchforks, hammers, chisels, brooms, laser-cutters and plasma-torches.... just all the stuff available to a mob of hysterical zealots.

Yeah Autoguns and Stubbers are probably cheaper up front than Lasguns. Ammo might be more costly in the long run, but when you're poor you have to take what you can get even if it's not as good for you in the long run.

Lasguns shouldn't have recoil by virtue of being lasers but they do anyway because 40K is World War 2 in space.

More like WW1 in space, really, outside specialist regiments like the Harakoni and the Elysians.

 Ratius wrote:
Lasguns are basically big torches given to unsuspecting guardsmen.
Do torches have recoil?

Do torches blow limbs off?

I always imagined lasguns firing big blasts of laser rather than being a thin beam and because of of that having recoil.

I'm pretty sure the artwork has displayed them as such too. I seem to remember a Necromunda piece of artwork showing a Goliath heavy taking so recoil as he fired a lascannon.