Steve Jackson Games - Site Navigation
Home General Info Follow Us Search Illuminator Store Forums What's New Other Games Ogre GURPS Munchkin Our Games: Home

Go Back   Steve Jackson Games Forums > Roleplaying > GURPS

Reply
 
Thread Tools Display Modes
Old 11-07-2017, 10:15 PM   #1
Kfireblade
 
Join Date: Dec 2015
Default Making more ammo stuck on a low tech world.

How hard would it be, realistically, for a high TL character thrown into a low TL world with the proper engineering and chemistry skills to make additional ammo? As I understand it primers are the hardest part of manufacturing new ammo. Assuming the character had access to a large vehicle (SM+7) with the TL 8 Mining and Factory systems from spaceships what would they need to find, and how hard would it be?
Kfireblade is offline   Reply With Quote
Old 11-07-2017, 11:06 PM   #2
Ulzgoroth
 
Join Date: Jul 2008
Default Re: Making more ammo stuck on a low tech world.

Primers might be easier than smokeless powder - you need more of it and making it takes lots of good-purity strong acid.

A TL8 factory system is a machine shop - it won't do the chemistry, though you could use it to make lab apparatus.

A mining system, regardless of TL, produces unrefined raw materials - a TL8 fabricator can't use raw minerals, it needs manufactured components. You'd need refinery systems - probably more than one to encompass metal-smelting, chemical preparation, and anything else. You could probably argue that the fabricator can convert refined materials into the components you need, in this context.

EDIT: If you can build out enough infrastructure, you don't need any especially exotic raw materials. You'll want glass and lead for working with the acid, sulfur to make sulfuric acid and nitrates to make nitric acid. Cotton might be the ideal cellulose base source. I think you might need acetone, not sure what you make that from. You may need mercury and/or some other components for the primers - I know three are a few candidates, but I don't know any of them particularly well.
__________________
I don't know any 3e, so there is no chance that I am talking about 3e rules by accident.

Last edited by Ulzgoroth; 11-07-2017 at 11:12 PM.
Ulzgoroth is offline   Reply With Quote
Old 11-07-2017, 11:29 PM   #3
Celjabba
 
Join Date: Sep 2006
Location: Luxembourg
Default Re: Making more ammo stuck on a low tech world.

It also depend on the weapon . shotgun/revolver ammo will be easier . And if you can afford to clean your weapon every few shots, you can use dirty propeller. But ammo for high rate of fire and automatic weapons will require more precise machining and smokeless powder.
Celjabba is offline   Reply With Quote
Old 11-08-2017, 06:33 AM   #4
mlangsdorf
 
Join Date: Aug 2004
Location: Austin, TX
Default Re: Making more ammo stuck on a low tech world.

What kind of weapon do they want to reload? A Spencer rifle firing black powder cartridges is a different problem than a G11 firing caseless than a UT ETK gun.

Assuming you want metallic cartridges, you're going to want:
* Lead or iron or copper, for the bullet
* Brass, iron, or bronze (copper and tin), for the cartridge itself
* Mercury, nitric acid, and ethanol, for the primer
** nitric acid can be made in various ways, but the modern industrial process uses ammonia as a feed stock and requires platinum for a catalyst; you can also use saltpeter, alum, and copper sulfate
** You can use potassium chlorate or potassium perchlorate instead, which require various potassium and sodium chemicals and are more difficult to make

Black powder is made from sulfur, charcoal, and saltpeter. You extract it from bat guano, mine it from fairly rare natural deposits, or synthesize it from nitric acid.

Smokeless powder can be made lots of different ways, but guncotton can be made from fine fabric threads, nitric acid, and sulfuric acid.

Caseless and ETC rounds are a lot more complicated, but it's basically the same stuff with some more exotic variants.

None of the chemistry involved is crazy hard or exotic: all the components were made by the 1860s historically. A lot of them are fairly dangerous to handle (mercury, chlorine gas, mercury fulminates) but normal lab safety procedures should be enough to avoid serious mishap. You've got access to TL8 manufacturing, so you can recast bullets and cartridges to the necessary tolerances.

As for finding the components:
* lead, iron, and copper are fairly common on Earth and have been mined since antiquity.
* mercury, sulfur, alum, and tin are rarer but are not terribly hard to find
* ethanol can be distilled from just about any sugar source
* saltpeter can be extracted from animal waste, so as long as there are bat caves or domesticated animals, you should be okay. Alternately, you can synthesize it from nitrogen in the air IF you can find platinum for the catalysts.
* cotton or equivalent threads come from certain plants or animal hair

A lone man would be hard pressed to find, mine, refine, and combine all those components into a single bullet. A lone man with access to an early trading system, like the early Roman Republic or early Chinese empires, could get everything he needed and then would just need to refine and put the pieces together.

There's also a separate question of scale: hand crafting out 100 blackpowder shotgun shells for your personal use is a lot easier than manufacturing 1 milliion .30-06 rifle rounds to equip the Roman Praetorian guard.
__________________
Read my GURPS blog: http://noschoolgrognard.blogspot.com
mlangsdorf is offline   Reply With Quote
Old 11-08-2017, 11:40 AM   #5
Kfireblade
 
Join Date: Dec 2015
Default Re: Making more ammo stuck on a low tech world.

Quote:
Originally Posted by mlangsdorf View Post
What kind of weapon do they want to reload? A Spencer rifle firing black powder cartridges is a different problem than a G11 firing caseless than a UT ETK gun.

Assuming you want metallic cartridges, you're going to want:
* Lead or iron or copper, for the bullet
* Brass, iron, or bronze (copper and tin), for the cartridge itself
* Mercury, nitric acid, and ethanol, for the primer
** nitric acid can be made in various ways, but the modern industrial process uses ammonia as a feed stock and requires platinum for a catalyst; you can also use saltpeter, alum, and copper sulfate
** You can use potassium chlorate or potassium perchlorate instead, which require various potassium and sodium chemicals and are more difficult to make

Black powder is made from sulfur, charcoal, and saltpeter. You extract it from bat guano, mine it from fairly rare natural deposits, or synthesize it from nitric acid.

Smokeless powder can be made lots of different ways, but guncotton can be made from fine fabric threads, nitric acid, and sulfuric acid.

Caseless and ETC rounds are a lot more complicated, but it's basically the same stuff with some more exotic variants.

None of the chemistry involved is crazy hard or exotic: all the components were made by the 1860s historically. A lot of them are fairly dangerous to handle (mercury, chlorine gas, mercury fulminates) but normal lab safety procedures should be enough to avoid serious mishap. You've got access to TL8 manufacturing, so you can recast bullets and cartridges to the necessary tolerances.

As for finding the components:
* lead, iron, and copper are fairly common on Earth and have been mined since antiquity.
* mercury, sulfur, alum, and tin are rarer but are not terribly hard to find
* ethanol can be distilled from just about any sugar source
* saltpeter can be extracted from animal waste, so as long as there are bat caves or domesticated animals, you should be okay. Alternately, you can synthesize it from nitrogen in the air IF you can find platinum for the catalysts.
* cotton or equivalent threads come from certain plants or animal hair

A lone man would be hard pressed to find, mine, refine, and combine all those components into a single bullet. A lone man with access to an early trading system, like the early Roman Republic or early Chinese empires, could get everything he needed and then would just need to refine and put the pieces together.

There's also a separate question of scale: hand crafting out 100 blackpowder shotgun shells for your personal use is a lot easier than manufacturing 1 milliion .30-06 rifle rounds to equip the Roman Praetorian guard.
I don't need caseless or ETK ammo, unfortunately I do want to go better then black powder. Now I actually am going to have a few tons of ammo and weapons with me in my cargo which will last awhile but not forever when I'm trying to build up a force. I do have access to a mid TL 4, early TL 5 in a couple places, infrastructure when it comes to trade.
Kfireblade is offline   Reply With Quote
Old 11-08-2017, 12:20 PM   #6
Anthony
 
Join Date: Feb 2005
Location: Berkeley, CA
Default Re: Making more ammo stuck on a low tech world.

Quote:
Originally Posted by Kfireblade View Post
I do have access to a mid TL 4, early TL 5 in a couple places, infrastructure when it comes to trade.
That simplifies things significantly, as most required feedstocks are available (if possibly requiring additional purification).

I would note, however, that TL 8 industrial machinery is specialized. It's certainly possible to have a refinery system that produces nitric acid and ammonia from air, water, and electricity (or several other ways of producing hydrogen, such as coal or natural gas); it requires catalysts that you probably can't make or replace at local tech, but they won't be any more of a problem than any of the other parts of your machinery that you can't make or replace with local tech.
__________________
My GURPS site and Blog.
Anthony is offline   Reply With Quote
Old 11-08-2017, 01:03 PM   #7
mlangsdorf
 
Join Date: Aug 2004
Location: Austin, TX
Default Re: Making more ammo stuck on a low tech world.

Quote:
Originally Posted by Kfireblade View Post
I don't need caseless or ETK ammo, unfortunately I do want to go better then black powder. Now I actually am going to have a few tons of ammo and weapons with me in my cargo which will last awhile but not forever when I'm trying to build up a force. I do have access to a mid TL 4, early TL 5 in a couple places, infrastructure when it comes to trade.
If you access to trading partners that can provide you refined copper, iron, mercury, and lead, as well as nitric and sulfuric acids, and you have enough wealth to buy the stuff from them, there's no reason you can't get all the raw materials you need. Then it's just Chemistry, Mechanic, Machinist, and Armory rolls to put everything together.

You can probably make the wealth necessary by buying the leftover slag from their precious metal mines and using your much more efficient Mining apparatus to extract even more precious metals from them.

The rules for making stuff with the Factory are on Spaceship 1 p 16. TL6 goods are 4 times as expensive at TL4 as they are at TL6, so .30 caliber ammo that costs $0.8 is going to have an effective price of $3.2 and require $1.5 in materials - you can crack out 5000 in an hour once you get going. That seems absurdly fast to me unless you have multiple assembly lines (and implies you can make a car in few hours...) but even a more reasonable 50-500 rounds/hour means that a day's work supplies you with a reasonable load of ammunition.
__________________
Read my GURPS blog: http://noschoolgrognard.blogspot.com
mlangsdorf is offline   Reply With Quote
Old 11-08-2017, 07:00 AM   #8
Anaraxes
 
Join Date: Sep 2007
Default Re: Making more ammo stuck on a low tech world.

Quote:
Originally Posted by Ulzgoroth View Post
acetone, not sure what you make that from.
During WWI, it was produced via a fermentation process from starch or sugars (molasses). Apparently with the right bacteria, you get a lot of acetone and butanol with only around 10% ethanol, sort of exactly what you don't want from your usual moonshine still.

If your tech base is even lower, medieval alchemists used to make their "spirit of Saturn" from a metal acetate (say, heating lead + vinegar (acetic acid), or dissolving limestone (calcium) in vinegar).

Modern commercial processes usually start with propylene (C3H6), which is a product of oil refining.

The last time I remember the topic coming around, some posters mentioned that the metallurgy for the brass cartridges was particular, and you'd get a lot more jamming or misfires with different brass (never mind different metals entirely, or lower-precision manufacturing methods versus the tolerance expectations of a modern mechanism).

Last edited by Anaraxes; 11-08-2017 at 07:22 AM.
Anaraxes is offline   Reply With Quote
Old 11-08-2017, 08:50 AM   #9
Fred Brackin
 
Join Date: Aug 2007
Default Re: Making more ammo stuck on a low tech world.

[QUOTE=Anaraxes;2133999The last time I remember the topic coming around, some posters mentioned that the metallurgy for the brass cartridges was particular, and you'd get a lot more jamming or misfires with different brass (never mind different metals entirely, or lower-precision manufacturing methods versus the tolerance expectations of a modern mechanism).[/QUOTE]

Making brass from scratch would indeed be difficult. One page I googled a few years ago had it be a 17 step process with multiple forming dies and 3 trips through an "annealing oven" which I'm not quite sure what is. Some sort of heat treatment.

If you've saved all your empty cartridges the next hard part is indeed the primers. The unmentioned/non-chemical issue is precision handling of very small quantities of the fulminate compound. I'd say that the only practical way to handle it is to build a primer-making machine. Good thing there's a deluxe machine shop in the plans.

It's going to be an enormous amount of work for just one man's ammo and if he's on an _alien_ world he might be needing to spend his chem lab time on finding/synthesizing vitamins and trace minerals.
__________________
Fred Brackin
Fred Brackin is offline   Reply With Quote
Old 11-08-2017, 09:23 AM   #10
malloyd
 
Join Date: Jun 2006
Default Re: Making more ammo stuck on a low tech world.

Quote:
Originally Posted by Fred Brackin View Post
Making brass from scratch would indeed be difficult. One page I googled a few years ago had it be a 17 step process with multiple forming dies and 3 trips through an "annealing oven" which I'm not quite sure what is. Some sort of heat treatment.
For brass you do that to relax the work hardening (which all copper alloys suffer from). It's not a real precise target temperature, several hundred degree range for brass, though of course the minimum time you need to hold it there is temperature dependent.

Annealing is usually something you do to relax internal stresses like work hardening in metals or differential cooling in glasses, though it presumably means something different in iron metallurgy.
__________________
--
MA Lloyd
malloyd is offline   Reply With Quote
Reply

Tags
ammo, gurps, high tl, low tl

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Fnords are Off
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 06:27 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.