Recoilless Pistol

[SpaceBadger]

I think it would be cool to have a weapon in Traveller to replicate the .75 cal recoilless pistol so often used by Slippery Jim di Griz, aka the Stainless Steel Rat.

I found an earlier thread discussing these as a type of mini-bazooka, or in Traveller terms a pistol-sized Accerator Rifle, firing rocket-propelled ammo. I don't recall the books going into that much detail; if they did, I must have missed it somehow on at least one re-read back in college when I wanted to port this into Traveller (alas, I can't currently locate those books ).

I wondered if it might instead work something like a design that Dean Ing specified for the "chiller" pistol carried by Ted Quantrill in several books. The chiller was specified to use ammo in which half of the cartridge was the propellant and half was a small reservoir of cold gas. When fired, the propellant burned to expel the slug, plus the cartridge case was combustible to add to the propellant force (and not require ejection). The cold gas then mixed w propellant gasses to reduce heat (and heat signature) and the cooled mixture was jetted out through vents in the weapon to counteract recoil from firing.

I have no idea whether Ing's engineering of this weapon was sound; as far as I recall, his areas of expertise are aircraft design and computer systems.

Anybody know if Ing's idea for a recoilless pistol would work, or have any better ideas to use instead?

*

PS: The specs, diagram, etc for the chiller appear in the first or second chapter of Ing's book "Single Combat"; the weapon appears in other books, but without all the technical details.

 

[mike wightman]

I've had accelerator pistols IMTU for years.

I just combined the stats for a snub pistol and normal pistol.

 

[madmike]

Recoilless weapons? I have them on my Weapons Index card system dating back to the early 80's.

 

[SpaceBadger]

Recoilless weapons? I have them on my Weapons Index card system dating back to the early 80's.

And do you intend to share?

 

[atpollard]

I have suspicions that a 'chiller' pistol will not really work ... sort of like the way the 'ice bullet' concept fails (there is just so much heat and energy in the propellant that it ends up shooting a cloud of steam).

What could store enough 'cold' to offset the energy of a chemical reaction?
And even if it did, wouldn't the cold stop the propellant reaction?
And even if it could exist, how do you insulate and handle something so dense and close to absolute zero in temperature?

 

[atpollard]

I suggest starting with a GYROJET PISTOL

And doing a search for 'Gyroc' weapons from other game systems.

 

[CosmicGamer]

Energy weapons seam to be the way to go if recoil is an issue. We are starting to do it at our current TL and in Traveller (depending on version) they are standard fare by TL9.

 

[lspitz]

A "recoilless" weapon requires a mechanism to redirect the equal-and-opposite energy of the recoil in such a way that it is not transferred to the weapon.

The simplest engineering approach is to make ammo that fires identical masses in opposite directions at the same velocity. One slug goes out the barrel towards the target; the other exits the gun in precisely the opposite direction through another barrel. The weapon itself remains stationary, since very little of the force is transferred to it.

But somehow I can't see this simple engineering solution as being practical, except possibly as a specialized one-shot murder-suicide weapon.

 

[sabredog]

I dunno, it just sounds like a snub pistol with better range is all you need for either a Chiller or the Rat's weapon. In either case they work the same, only they shoot farther.

Probably with more gas being vented out the sides of the recoilless pistol (out the rear would be....alarming) so that it wouldn't be so much "recoilless" as just having a better control of the muzzle while firing a rocket-assist type of round. Maybe even a two-stage round that is sort of lobbed out a short distance to reduce recoil to negligible relative to the size and initial velocity of the round, and then the second stage kicks in to accelerate it to the target like a little ATGM with target memory guidance. Just let it see the target and let 'er fly.

For the Chiller I'd just go with the regular snub autopistol variant with greater range and a low signature by using the same sort of two-stage system if you really have to have that.

Aside from the reasons in the books having to do with plot and cool signature weapon for the protagonist (though I was less than thrilled with them) why have that in Traveller? Its a pistol - so given its short relative range for realistic accuracy what it more important to mask: the sound, heat signature, or the guy firing it?

 

[SpaceBadger]

Not really looking for either rocket guns or energy weapons. As stated in OP, the idea is to simulate the recoilless pistols used by the Stainless Steel Rat.

Maybe something like the Balanced Automatic Recoil System used in the AK-107, which is stated to eliminated felt recoil and muzzle rise.

Or something venting propellant gasses like the original recoilless rifle mini-artillery, but in pistol size, and not venting the hot gas straight back into the shooter's face.

 

[SpaceBadger]

I dunno, it just sounds like a snub pistol with better range is all you need for either a Chiller or the Rat's weapon. In either case they work the same, only they shoot farther.

That may be the best thing to do for the Rat's guns, although I'm thinking larger projectile (abt 18mm) for more damage rather than longer range. Doesn't seem as good a fit for the Chiller, but I can get along fine without that.

Aside from the reasons in the books having to do with plot and cool signature weapon for the protagonist (though I was less than thrilled with them) why have that in Traveller? Its a pistol - so given its short relative range for realistic accuracy what it more important to mask: the sound, heat signature, or the guy firing it?

Good point. Maybe it's just an 18mm snub pistol.

 

[sabredog]

Yeah, I picture it OK, that's why the gases need to vent out the sides of the barrel or breech rather than the rear. In RL something like what is in the Stainless Steel Rat wouldn't work without burning off your face - they are humorous scifi after all and just need zoomy weapons - not the real thing.

The reason I suggested the two-stage system is because you'll lose a lot of the power of the propellant charge just venting off like an RR does. A real RR is big - even a Carl Gustav is a lot bigger than a handgun. And even for their size their range is a lot shorter than a conventional round of the same caliber.

With something pistol sized, maybe 15-20mm max (again, having to assume REALLY efficient propellant here) you are already limited to pistol range for the caliber since you are limited in propellant and the weight of the round. A slow, heavy round will drop a lot faster than a light high velocity one. I know you know that but it is worth restating when considering the design of this thing because even if the round is the size of a 20mm Anzio round once you vent enough gas to make the thing useable as a pistol you've probably reduced it's range and accuracy to the same as you'll get out of a snub pistol, and less than a grenade launcher for less effect.

That's why I figured a zoomy weapon needs a two-stage mini-rocket launching system and smart guidance to hit the target. No real recoil and all the accuracy with respectable range.

So how far does it have to go to be effective? Does it rely on the warhead for all of its damage? How hard is the thing going to be to aim? Why wouldn't a 20 or 40mm grenade auto launcher with a 5-6 round magazine suffice?

 

[SpaceBadger]

Yeah, I picture it OK, that's why the gases need to vent out the sides of the barrel or breech rather than the rear. In RL something like what is in the Stainless Steel Rat wouldn't work without burning off your face - they are humorous scifi after all and just need zoomy weapons - not the real thing.

The reason I suggested the two-stage system is because you'll lose a lot of the power of the propellant charge just venting off like an RR does. A real RR is big - even a Carl Gustav is a lot bigger than a handgun. And even for their size their range is a lot shorter than a conventional round of the same caliber.

With something pistol sized, maybe 15-20mm max (again, having to assume REALLY efficient propellant here) you are already limited to pistol range for the caliber since you are limited in propellant and the weight of the round. A slow, heavy round will drop a lot faster than a light high velocity one. I know you know that but it is worth restating when considering the design of this thing because even if the round is the size of a 20mm Anzio round once you vent enough gas to make the thing useable as a pistol you've probably reduced it's range and accuracy to the same as you'll get out of a snub pistol, and less than a grenade launcher for less effect.

That's why I figured a zoomy weapon needs a two-stage mini-rocket launching system and smart guidance to hit the target. No real recoil and all the accuracy with respectable range.

So how far does it have to go to be effective? Does it rely on the warhead for all of its damage? How hard is the thing going to be to aim? Why wouldn't a 20 or 40mm grenade auto launcher with a 5-6 round magazine suffice?

You're right, probably not a realistic practical weapon.

Maybe a specialty gun, using the mechanical piston for recoil reduction as in the AK-107, rather than gas venting. Would probably look something like a Star Wars blaster in size, but firing these big 18mm slugs. I just like the idea of somebody being able to haul one out at an appropriate time and say, "That's not a gun. THIS is a gun!"

 

[sabredog]

Oh hey, I'm with you on that. My ATU's Marines have a signature sidearm that is called the Tannhauser. It's an 17mm autopistol that fires HE rounds from carbine casings, and has an ominous recoil. It doesn't use a Dex modifier, but a Strength one for mods. However, as they say in the service, "The fights over when the fat lady sings!"

Sure it doesn't get used much in a real battle, and it isn't any more accurate or hit significantly farther than any other autopistol or revolver, but it does get people's attention when waved at them. And it does hit hard and make it easier to get through armor at short range. But ultimately it exists because it follows the Rule Of Cool.

 

[RatPatrol]

The Vector SMG / Pistol Directs the recoil energy down, instead of back .....


KRISS Vector

http://www.youtube.com/watch?v=cqw2ENtN9s8

 

[madmike]

Oh hey, I'm with you on that. My ATU's Marines have a signature sidearm that is called the Tannhauser. It's an 17mm autopistol that fires HE rounds from carbine casings, and has an ominous recoil. It doesn't use a Dex modifier, but a Strength one for mods. However, as they say in the service, "The fights over when the fat lady sings!"

Sure it doesn't get used much in a real battle, and it isn't any more accurate or hit significantly farther than any other autopistol or revolver, but it does get people's attention when waved at them. And it does hit hard and make it easier to get through armor at short range. But ultimately it exists because it follows the Rule Of Cool.

Name rings a bell. Warren Norwood novels?

My Tannhauser is a TL8-9 laser pistol