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Old 09-20-2017, 08:05 PM   #1
hal
 
Join Date: Aug 2004
Location: Buffalo, New York
Default Binary propellant and Standard TL 8 guns?

Hello Folks,
Quickie question time...

Binary Propellants in Ultratech tell us to modify the caseless rounds stats for guns per the written rules.

My question is:

How does it modify the stats of TL 8 guns using standard cased ammunition?

Hal
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Old 09-20-2017, 08:26 PM   #2
Fred Brackin
 
Join Date: Aug 2007
Default Re: Binary propellant and Standard TL 8 guns?

Quote:
Originally Posted by hal View Post
Hello Folks,
Quickie question time...

Binary Propellants in Ultratech tell us to modify the caseless rounds stats for guns per the written rules.

My question is:

How does it modify the stats of TL 8 guns using standard cased ammunition?

Hal
It modifies ammo weight mostly. If you have bullet weights for your target TL8 guns liquid propellant uses "naked" bullets plus the weight of the liquid propellant.

As I know of no truly good candidates for the two chemicals to used as binary components it's hard to give you a realism-based guesstimate of propellant mass.
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Old 09-20-2017, 09:46 PM   #3
clu2415
 
Join Date: Jun 2016
Default Re: Binary propellant and Standard TL 8 guns?

Liquid propellant is incompatible with cased ammunition. There are four parts to ammunition: projectile, case, propellant, and primer. A liquid propellant firearm measures out propellant from a tank instead of parcelling it with each round (eliminating the need for a case) and ignites the propellant (eliminating the need for a primer).

The ballistics of any TL8 round can be duplicated using liquid propellant.
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Old 09-20-2017, 09:49 PM   #4
Anthony
 
Join Date: Feb 2005
Location: Berkeley, CA
Default Re: Binary propellant and Standard TL 8 guns?

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Originally Posted by hal View Post
How does it modify the stats of TL 8 guns using standard cased ammunition?
It doesn't; it's not an available conversion (there's some artillery that could theoretically be modified, but it would be an extensive modification, not just a standard change).
Quote:
Originally Posted by Fred Brackin View Post
As I know of no truly good candidates for the two chemicals to used as binary components it's hard to give you a realism-based guesstimate of propellant mass.
Though it mostly doesn't matter. Propellant is generally less significant than either bullet or case when considering ammunition weight.
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Old 09-20-2017, 11:03 PM   #5
hal
 
Join Date: Aug 2004
Location: Buffalo, New York
Default Re: Binary propellant and Standard TL 8 guns?

Would it be possible to guestimate what the energy in joules per gram of the binary propellant might be by chance?

The problem here is that we can get real life data on real life bullets, and get the damage values from there. But if the Binary Propellant rules were intended to work with caseless rounds, then we're kinda SOL (Stuck onna limb for the G rated version).

GURPS VEHICLES made the assumption that the damage of the bullets would increase with TL because of the propellants used. If I can get a ballpark estimate of what the propellant is relative to modern smokeless powder, that would be nice.
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Old 09-21-2017, 08:36 AM   #6
lwcamp
 
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Join Date: Nov 2004
Location: The plutonium rich regions of Washington State
Default Re: Binary propellant and Standard TL 8 guns?

Quote:
Originally Posted by hal View Post
Would it be possible to guestimate what the energy in joules per gram of the binary propellant might be by chance?

The problem here is that we can get real life data on real life bullets, and get the damage values from there. But if the Binary Propellant rules were intended to work with caseless rounds, then we're kinda SOL (Stuck onna limb for the G rated version).

GURPS VEHICLES made the assumption that the damage of the bullets would increase with TL because of the propellants used. If I can get a ballpark estimate of what the propellant is relative to modern smokeless powder, that would be nice.
Probably something like 98% hydrogen peroxide solution + kerosene. Or look up any list of liquid rocket fuels/oxidizers.

Luke
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Old 09-21-2017, 09:35 AM   #7
hal
 
Join Date: Aug 2004
Location: Buffalo, New York
Default Re: Binary propellant and Standard TL 8 guns?

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Originally Posted by lwcamp View Post
Probably something like 98% hydrogen peroxide solution + kerosene. Or look up any list of liquid rocket fuels/oxidizers.

Luke
I'm thinking that the propellant has to be a bit more stable than rocket fuel oxidizers simply on the grounds that a hit against the two bottles by a bullet could set off a secondary explosion.

Depending on the gun, the statement made was that the magazine would hold enough propellant to fire off three magazines. For the heavy pistol, that would be 60 shots (possibly 63) and a medium pistol would hold 90 shots (possibly 93). For an assault carbine - that would be 150 shots! For a Gatling Carbine? That would be 600 shots!

That's a heck of a fair amount of explosive propellant available for a secondary explosion for a freshly loaded gun. :(

Real world data exists for muzzle velocity, smokeless powder mass, and bullet mass, which permits us to determine what the energy content of the smokeless powder has to be in the neighborhood of. What we don't have is the bullet mass of the actual caseless bullets themselves, the propellant mass for the caseless bullets, nor the actual velocity of the bullets. In other threads, there have been questions on whether or not the Caseless data is essentially pulling numbers out of thin air or not. The possible exception to this may be the G-11, but the formula from Doug Cole's spreadsheet seems to fail when talking about caseless Ammo for some odd reason. :(
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Old 09-21-2017, 10:04 AM   #8
Fred Brackin
 
Join Date: Aug 2007
Default Re: Binary propellant and Standard TL 8 guns?

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The possible exception to this may be the G-11, but the formula from Doug Cole's spreadsheet seems to fail when talking about caseless Ammo for some odd reason. :(
The G-11 has nothing to go with binary liquid propellant and will not yield you any data relevant to the question.

You have the data for the bullets that would be used with liquid propellant. They're the same bullets used in cased ammo at equivalent velocities. Liquid propellant would just do away with the gunpowder and the cartridge that holds it.

If you think lwcamp's suggestions for propellant are much too dangerous for practical use that probably means the idea isn't practical.
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Old 09-21-2017, 11:37 AM   #9
Anthony
 
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Default Re: Binary propellant and Standard TL 8 guns?

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Originally Posted by hal View Post
I'm thinking that the propellant has to be a bit more stable than rocket fuel oxidizers simply on the grounds that a hit against the two bottles by a bullet could set off a secondary explosion.
That's a pretty low probability situation, and without a containment vessel, will usually just result in a fire.
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Real world data exists for muzzle velocity, smokeless powder mass, and bullet mass, which permits us to determine what the energy content of the smokeless powder has to be in the neighborhood of.
Or you can look up the properties of nitrocellulose. Plausible TL 8 solid propellants have an energy density of 4-5 kJ/g, though guns typically only have an efficiency of 20-30%. Likely (non-cryogenic) binary propellants are similar, the theoretical benefits of liquid propellants aren't based on energy density.
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Old 09-21-2017, 01:38 PM   #10
Bilanthri
 
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Default Re: Binary propellant and Standard TL 8 guns?

I find myself wondering if this idea was modeled after bombardier beetles.
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