Snub Pistol Errata

[Diveguy]

I agree, but had no data on density (or volume ratio of shell to charge). I use what I can Google as a starting point.
Any idea the density of PETN?

C4 sits at @ 1.73 g/cm3; while PETN is about 1.75 g/cm3 - it's less an issue of density in my opinion (talking as a bomb tech here, not as someone who's made explosive projectiles haha) - more the sensitivity issue, or relative lack-of for C4. C4 is *designed* to be stable and safe to handle on the battlefield, so it needs a nice "kick" to set it off (to very simplify things). PETN on the other hand, in pure form, is much more sensitive to insult, and thus would be easier to initiate in that small of an amount. Yet, as pointed out, make it *too* sensitive and the reaction from firing will set off the round in the chamber.

BUT - I agree with several of the posters, and would hand-wave it in my games as well. Given that Traveller already postulates gravitationally-polarized explosives as canon (and, man, I would LOVE to have the chance to play with something like that IRL!), I'm willing to accept that a couple thousand years from now they've also developed a way to make a 10mm explosive projectile.

Similarly, given the intended use-case of zero-G combat, I would want to remove as much mechanical action as possible, partly due to the inertia factors and partly to reduce points of failure from items trying to move in vacuum. Instead of a rotating cylinder, I'd look at a fixed cartridge with multiple barrels, and electrically fire the above-mentioned caseless rounds. Put in some sort of piston-capture system to help contain the gasses and counter the recoil action.

Oh, and there's a whole lot of that concept which *isn't* theoretically, and has actually been deployed for almost 40 years. Say hello to the underwater snub-gun - The Heckler and Koch P11:

HK P11

That's been out there since 1976, and the Russians have their own version the SPP-1.

 

[atpollard]

Can't be much heat production.

Make the round caseless.

I like caseless ammo. Is there any Traveller TL references for caseless ammo?

 

[kilemall]

I like caseless ammo. Is there any Traveller TL references for caseless ammo?

Only the ACR family. No big deal.

I like the Armory annd Ordnance alternate rules tech hierarchy of caseless then electrothermal.

 

[whartung]

Learned a very interesting problem with caseless ammo.

Heat.

A benefit of cartridge ammo is the casing absorbs a lot of heat, and is then tossed aside. Whereas with caseless, the action has to consume and manage all that heat. As I understand it, this is one of the reasons caseless weapons are not a "thing" yet (not necessarily the only reason, just "a" reason).

But that brings up another conversation about some of the modern plastic and polymer casing experiments.

Several new cartridge designs for the new infantry rifle were polymer cased, but those designs were rejected (again, not necessarily because of the polymer design -- no idea what, if any, impact that had on the decision process). Simply that there were several designs like that, and those were, in the end, rejected. The current cartridge is a hybrid steel and brass casing.

From Wikipedia:

Its hybrid three-piece cartridge case has a steel case head and brass body connected by an aluminum locking washer to support the high chamber pressure of 80,000 psi (551.6 MPa).

 

[Spinward Flow]

Learned a very interesting problem with caseless ammo.

Heat.

A benefit of cartridge ammo is the casing absorbs a lot of heat, and is then tossed aside. Whereas with caseless, the action has to consume and manage all that heat. As I understand it, this is one of the reasons caseless weapons are not a "thing" yet (not necessarily the only reason, just "a" reason).

But that brings up another conversation about some of the modern plastic and polymer casing experiments.

Several new cartridge designs for the new infantry rifle were polymer cased, but those designs were rejected (again, not necessarily because of the polymer design -- no idea what, if any, impact that had on the decision process). Simply that there were several designs like that, and those were, in the end, rejected. The current cartridge is a hybrid steel and brass casing.

Sadly, the plastic ammo option did not wind up being selected ... but the fact that the plastic acts as a head INSULATOR rather than a heat CONDUCTOR has some very interesting knock on effects for use in continuous rapid fire weapons.

 

[Condottiere]

Caseless ammunition for automatic smallarms needs a technological level upgrade.

In this specific case, you stuff the round into a revolver cylinder chamber.

 

[whartung]

Sadly, the plastic ammo option did not wind up being selected ... but the fact that the plastic acts as a head INSULATOR rather than a heat CONDUCTOR has some very interesting knock on effects for use in continuous rapid fire weapons.

7:45 in the above video talks about this.

I did not know this, I had not considered the polymer casing being an insulator. That's a fascinating aspect of this. Notably the 10% lesser charge necessary for the same velocity, and that the chamber is cool to the touch after firing. It's amazing that the insulator is so good that even being so thin, it has this affect on the overall mechanism.

 

[Spinward Flow]

I did not know this, I had not considered the polymer casing being an insulator. That's a fascinating aspect of this. Notably the 10% lesser charge necessary for the same velocity, and that the chamber is cool to the touch after firing. It's amazing that the insulator is so good that even being so thin, it has this affect on the overall mechanism.

I suspect that although the US Army passed on the plastic case option for now, the next "big thing" in small arms battle rifle(-ish) follow on to the switch to 6.8x51mm chamber dimensions is going to be the further development of plastic cases for ammo. It's simply too much of a step change for capability and logistics to be left on the trash heap. Put some more development work and funding into plastic cased ammo and I can easily envision a circumstance in which a number of rifle rounds get switched over from brass to plastic casing in the next decade (or so).

But yeah, the Insulator Factor means that less of the propellant energy is getting "wasted" heating up the brass casing, forcing more of that heat (and therefore, pressure) energy to be usefully directed into propulsion of the projectile down the barrel. The plastic insulator casings are simply more "energy efficient" at turning powder grains into meters/second of muzzle velocity, in addition to reducing thermal bleed into the receiver while also being lighter per ammo count making logistics easier and increasing the number of magazines that can be carried for a given weight allowance. It's just a whole lot of compounding advantages that all add up to being an advantage in the field ... once you've worked the kinks out of the manufacturing and training processes.

Also, Chris Cappy is a really good amateur youtuber for all this milspec stuff, being a former infantryman himself.

 

[Condottiere]

It's all coming down to logistics and standardization.

Supposedly, it's no longer amateur hour.

The thing about the case it has a number of traits and fulfills a number of rather useful functions: container, pressure containment, heat sink.