Snub SMG Questions

[Aramond]

I was wondering what you all feel are the features that make a Snub SMG and Snub weapons Low recoil.

Snub to me has always signified a short barrel length, which usually equates to a less controlable firearm with more muzzel climb.

I would assume with their lower velocities snub weapons would be easier and more effetivly suppressed/silenced.

Also could a Snub weapon be loaded with a more convetional round as well as the classic low velocity rounds? And what perfomance differnce would be expected?

I am asking this question as part of a discussion that is going on among the members of The Corsairs of the Ebon Main PBEM game we discussing s new "standard" weapon for our pirate crew and I am working on a proposed design and am looking for some ideas to add to it.

 

[Tucker]

OK, what's a Snub SMG? Is this some cool T20 chopper? It ain't in any of my CT/MT stuff.

I'm gonna guess the thing is an auto-fire capable version of the Combat Snub Pistol, an auto loader instead of wheel-gun, and 20+rd mag and possibly a folding stock?

I too was sorta thrown by the nomenclature of 'snub'. It means short little barrel to me, as intro'd to me by countless TV cops. I dunno, the Traveller version is sorta a big damn pistol, maybe the cartridges are squatty or something.

 

[far-trader]

If we're talking the same weapon then to me the major difference from other slug throwers is that all Snub type ammo is gyrojet powered. The low recoil is due to the low initial velocity and relatively heavy weapon.

The characteristic short barrel (and imo the reason for the name) is enough given the low velocity and once the round clears the end of the barrel the fuse fires the round's jet to kick it up to more normal bullet velocity and add more spin (though still subsonic iirc).

 

[Tucker]

Really? I sort of wish Book 4 had taken the trouble to go into that. Maybe the write-up in MT gives it the gyrojet thing. Or are you thinkin' the Accelerator rifle or MT's ARL?

 

[hunter]

Snub weapons fire low-velocity cartridges of large caliber.

Traveller's Aide #1 tells all
Suitable for use with CT and T20...(also available in print)

Hunter

 

[Todg]

Book 4 descripbes the Snub pistol as firing a "10mm, 7g bullet at 10-150 meters per second". It is not a rocket firing round, since the Accelerator Rifle mentioned right after it specifically is.

It should be noted that such a weapon would deliver a mere 79J of energy. Compare this with the (Traveller) 9mm autopistol with around 1000J of energy and there quite a difference. The 10mm snub actually has about half the muzzle energy of a .22LR, and so would require some kind of explosive bullet to do anything more than break the skin.

The Snub SMG, and Snub carbine are just variations on this weapon. In general, the statistics for CT weapons should be considered suspect. Closer examination shows most of them to be at quite a variance with RL versions. The Traveller 9mm is almost 2x as powerful as the RL version, and the Snub pistol is rediculously small and light - far smaller and ligher than the smallest .38 caliber revolver currently made.

There is also room for doubt as to the effectiveness of any 10mm HEAT round. The penetration of a HEAT round is directly proportional to its diameter, and the volume of explosive that can be fitted in so small a heat round (when you factor in the volume lost to the shaped charge, and the detonator) turn out to be rather puny.

 

[far-trader]

Originally posted by Tucker:
Really? I sort of wish Book 4 had taken the trouble to go into that. Maybe the write-up in MT gives it the gyrojet thing. Or are you thinkin' the Accelerator rifle or MT's ARL?

Hmm, not sure where I'm remembering the gyrojet from, might be MT or it could be a recall fubar

Or maybe some home-built bastard of an accelerator rifle. I may have to go digging in what's left of my old Traveller. I think it might have been the result of noting like Corejob mentions that you just don't get much effect with the low velocity, even if a HEAP round. Of course it could be a depleted unobtanium round

and the HEAP might be explosive handwavian

 

[Todg]

Even if it is a gyrojet round, that's not a big plus. Gyrojet was a commercial failure for good reason. The round had no energy at short range and no accuracy at long range.

There are better solutions.

 

[mike wightman]

There are better solutions.

Such as .... (hint, hint )

 

[Todg]

Laser weapons, for one. These have (effectively) no recoil.

 

[mike wightman]

Yep, but can you think of a way to have a low recoil, propellant based, firearm for low-G use?
How about miniature solid rockets with limited target tracking? They could be launched/fired at very low velocities but then accelerate to high velocity once the solid rocket kicks in. The lack of direct fire accuracy could be made up by having a fire-and-forget type miniature guidance system built into the round.
TL10+ ???

 

[Aramond]

At that point Sigg we are talking about a "Smart" Accelerator rifle.

Corejob I was wondering in general I have always pictured the Snub SMG as being verry similar to a Ingram MAC type, fireing from open bolt position (I believe that I have read onthe many discussions here that anopen bolt mechanism has less effective recoil than a closed boltam I correct?) with rounds that were possibly a combination of minor rocket assist with a low velcoity ignition/ejction charge to shove it down the barrel at the listed muzzel velocity.

Obviously this weapon require a generous dose of hand-wavium in order to work as described. So I feel it is not a good base for the project.

Corejob what aspect of a weapons design lead to the least recoil in a weapon of a type similar to say a FN P90, as this is the weapon I pushing to use as a base for our 'Pirate Close quareters combat weapon'. I am assuming caseless rounds for this. We are also thinking about an integral or optional silencer.

Thoughts from all please.

 

[Morte]

Originally posted by Sigg Oddra:
Yep, but can you think of a way to have a low recoil, propellant based, firearm for low-G use?
How about miniature solid rockets with limited target tracking? They could be launched/fired at very low velocities but then accelerate to high velocity once the solid rocket kicks in. The lack of direct fire accuracy could be made up by having a fire-and-forget type miniature guidance system built into the round.
TL10+ ???

If it's TL10+, why not stick with lasers... What we really need here is something at TL8 that's mechanical and cheap, to fill the role of the nonsensical snub weapons.

This might work, but it's not going to be cheap: At TL8 you could have a slug thrower with some sort of AG thruster built in that supplies a jolt to cancel the recoil. I'd expect we're looking at some sort of high velocity sabot/fletchette round again.

 

[mike wightman]

If it's TL10+, why not stick with lasers...

The weight and bulk of the backpack for one, cost for two, and thinking about it again it's probably possible at TL9 (the accelerator rifle is, and the electronics should be possible by then ).

 

[Todg]

Originally posted by Sigg Oddra:
Yep, but can you think of a way to have a low recoil, propellant based, firearm for low-G use?
How about miniature solid rockets with limited target tracking?

Probably not too small since you'd need a steerable motor to turn the projectile (assuming vacuum, steerabel fins won'r work). What you have is in essence a small ATGM, with all the costs that implies.

Certainly, rockets would work, and they don't even have to be slow or accelerate slowly. The M72 LAW uses up all it's propellant while in the tube and has no recoil.

Or for something with a real wallop, consider the LOSAT. It's a rocket that accelerates up to tank gun velocities and uses a kinetic kill. You could build a smaller version.

The probelm with the GyroJet (IMHO) is that they tried to make the rocket bullet sized and primer fired. The technology just wasn't up to the task. Why not build something a little larger and more capable?

A pistol design is certainly a problem if you are using rocket propulsion (backblast in the face). A rifle or carbine would be easy - just put the exhaust over the shoulder and make sure no one stands behind you.

 

[Todg]

Originally posted by Aramond:
Corejob I was wondering in general I have always pictured the Snub SMG as being verry similar to a Ingram MAC type, fireing from open bolt position (I believe that I have read onthe many discussions here that anopen bolt mechanism has less effective recoil than a closed boltam I correct?) with rounds that were possibly a combination of minor rocket assist with a low velcoity ignition/ejction charge to shove it down the barrel at the listed muzzel velocity.

Well, the MAC-10 is a rather horrible SMG, IMHO. It's really only good for high concealment and spraying the occupants of a room. It rather hard to shoot accurately at any distance.

It is true that open bolt guns, using a mechanism called API (Advanced Primer Ignition) do have less recoil than closed bolt guns because the round has to absorbe the forward momentum of the bolt before it can drive the bolt, and ultimately, the gun, to the rear. These guns are generally difficult to shoot accurately on semi-auto due to 'bolt slap' but is full auto, this is not an issue.

There is an even more extreme version of this form of recoil elimination called 'soft recoil'. This system is used on the Browning 'Recoilless' shotgun, the XM-307 OCSW, and several light armored vehicles. In this case, the whole barrel and receiver assembly are held to ther rear under spring tension. When the weapon is fired, the assemblie is released to fly forward, and at a predetermined point, the round is fired will the barrel/receiver is moving forward. This forward momentum effectively cancels out almsot all of the recoil generated.

Corejob what aspect of a weapons design lead to the least recoil in a weapon of a type similar to say a FN P90, as this is the weapon I pushing to use as a base for our 'Pirate Close quareters combat weapon'. I am assuming caseless rounds for this. We are also thinking about an integral or optional silencer.

Well, sinlencers make very good muzzle brakes, and do reduce recoil to a certain extent. It will depend on the environment you are shooting in. In Zero G, whatever momentum the bullet has, the shooter will also get.

If you fire a 7g projectile at 100m/s (Snub pistol) then the shooter will pick up 7mm/sec velocity in the opposite direction assuming a 100kg shooter.

In general, however, felt recoil is dependant on recoil energy and the larger the mass of the gun, and the smaller the mass of the projectile, the smaller the recoil energy.

Using your P90 as a platform, you'll do best if you keep your projectile very light and compensate by adding velocity. Keep in mind that the propellant add to the recoil as well, so gauss weapons have a distinct advantage.

 

[Aramond]

Corejob, Gauss weapons have been ruled out on account of cost. I was really thinking of some thing that a dual magazine feed capability, one mag loaded with a standard 10mm pistol type round and the second with a snub type tranq or something else. As a shipboard close combat weapon we would be looking for good penetration on everything up to cloth, little chance of penetration of shipboard equipment. frangible rounds came to mind I understand that their perfomance against cloth would probably be poor. Also long range perfomance is not considered a requirement for this weapon, and a TL A or B as cap.

Also what is your professional opinion of the FN P90 an interesting weapon from what I've read, and the integrated triple sight rail system allows for some interesting combinations.

 

[kaladorn]

Originally posted by Corejob:
variance with RL versions. The Traveller 9mm is almost 2x as powerful as the RL version, and the Snub pistol is rediculously small and light - far smaller and ligher than the smallest .38 caliber revolver currently made.

Which is funny, considering the visual depictions of the revolver and AP snub pistols in MT clearly show them as bulkier than conventional pistols. So the light mass is even more suspect.

Yes, trying to reconcile the trivia of the minute stats of the CT weaponry is a waste of effort. I just look at what the thing does in game terms, a general description of how it is described, and usually the depiction of it, to get an idea what it must weigh. I don't worry much about muzzle energy, as no PC has ever asked! I take the published stats for pen/atten/dmg and assume that the appropriate amount of propellant and slug are present to produce those.

 

[womble]

I always envisaged the snub pistol as having a dirty great calibre - 30mm or more - so it could pack a significant enough warhead to inflict damage on personnel whenit was only travelling at baseball speeds. Its light weight comes from not having to sustain a terribly powerful propellant 'bang' or have a heavy frame to reduce felt-recoil. The huge calibre also gave it a good reason to be a revolver. But I never tried to draw it or do any 'realistic' sums about how hard to conceal it'd be...

 

[Andrew Boulton]

Well, the MAC-10 is a rather horrible SMG

There's a cute bit in the '80s B-movie "Night of the Comet", (in which two sisters were conveniently indoors when a passing comet killed most of the population and turned the rest into zombies). The older sister finds a couple of Mac-10s, which keep jamming at critical moments. The younger sister says, "Daddy would've gotten us Uzis!"