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 04-30-2016, 11:52 PM   #51
Ulzgoroth
 
Join Date: Jul 2008
Default Re: What kinds of firearms would people start making [After the End]?

Quote:
Originally Posted by malloyd View Post
and breach loaders (which are essentially impossible to get a good seal for at an affordable price without brass cartridges).
Uh, how do shotguns work then?
Quote:
Originally Posted by malloyd View Post
And explosives chemistry is very tricky and *incredibly* dangerous. People telling you about how easily high school chemistry teachers can turn out picric acid are neglecting to mention that the ordinance works of a dozen 19th century armies and navies worked on the stuff for a couple decades and never managed to make it in bulk stable enough for mass issue anybody was happy with.
Of course, what picric acid was never really satisfactory for (though it was used nonetheless) was high explosive filler for shells. As a material for percussion caps or primers, its instability might be a lot less of a problem.
__________________
I don't know any 3e, so there is no chance that I am talking about 3e rules by accident.
Ulzgoroth is offline   Reply With Quote
Old 05-01-2016, 04:48 AM   #52
Polydamas
 
Join Date: Jan 2006
Location: Central Europe
Default Re: What kinds of firearms would people start making [After the End]?

Don't shotgun shells usually have a brass base and a cardboard or plastic upper?

Quote:
Originally Posted by malloyd View Post
The hard part of firearms manufacture is the ammunition.

This is the limiting issue for both sophisticated actions (which will quickly get so fouled as to not work without smokeless powder) and breach loaders (which are essentially impossible to get a good seal for at an affordable price without brass cartridges). Guns aren't trivially simple machines, but they aren't that complex either. The kind of TL4 craftsmanship that can build clocks or automatic toys or articulated plate armor is more than good enough to build any production gun ever produced. It's manufacturing ammunition, particularly in large enough quantities at affordable prices, that is going to be the limiting factor.
I know that house style discourages it, but I strongly wish that S.A. Fisher and Hans had bucked the trend and included short bibliographies in Pyramid 3-88 and HT Adventure Guns. I trust their expertise ... but I still have some questions, and in the Wasteland trusting gets you dead. Citing a good history of ammunition from the middle of the 19th century to the middle of the 20th would only cost ten words, and would give lots more information on how different styles of cartridge are constructed and what did and did not work with black powder.

There are many parts of the world where individual families made enough black powder to keep themselves in hunting (I am told that the most accessible ones are memoirs of Appalatia in the Depression). The real obstacle seems to be that its a process which has to be passed down in person; several attempts to create saltpeter from manure by people with degrees, money, and lots of books have failed. Smokeless powder and brass cases are more complicated and its much harder to find criminals making them in a basement than to find them improvising firearms out of cap guns or staplers.

One Taliban Kalashnikov magazine shown to C.J. Chivers contained rounds from 10 to 40 years old, and a Lee-Enfield magazine might have contained even older rounds, but rounds like that have poor reliability and accuracy.
__________________
"It is easier to banish a habit of thought than a piece of knowledge." H. Beam Piper

This forum got less aggravating when I started using the ignore feature
Polydamas is offline   Reply With Quote
Old 05-01-2016, 07:03 AM   #53
malloyd
 
Join Date: Jun 2006
Default Re: What kinds of firearms would people start making [After the End]?

Quote:
Originally Posted by Ulzgoroth View Post
Uh, how do shotguns work then?
They have a brass cartridge, it's just shallow. The seal is provided by the pressure expanded cylinder of brass pressing against the barrel bridging the breach. It doesn't need to be a very long cylinder to do that.

Quote:
Of course, what picric acid was never really satisfactory for (though it was used nonetheless) was high explosive filler for shells. As a material for percussion caps or primers, its instability might be a lot less of a problem.
It'll be worse in a normal percussion cap, since one of the major problems is reaction with metals to form even more unstable explosives. In a paper tape it will dry out and crystalize fairly quickly (also bad). I suppose plastic caps or tapes might not be much worse than mercury fulminates.

Edit: I think the least crazy materials for make your own percussion caps are probably perchlorates. Sodium perchlorate is not too insanely volatile and fairly easy to make from salt and DC current, and if you are making black powder you already have some potassium counterions from somewhere (for the saltpeter) to convert it to something less hygroscopic.
__________________
--
MA Lloyd

Last edited by malloyd; 05-01-2016 at 07:21 AM.
malloyd is offline   Reply With Quote
Old 05-01-2016, 08:44 AM   #54
acrosome
 
acrosome's Avatar
 
Join Date: Aug 2010
Location: The Land of Enchantment
Default Re: What kinds of firearms would people start making [After the End]?

Quote:
Originally Posted by malloyd View Post
People telling you about how easily high school chemistry teachers can turn out picric acid are neglecting to mention that the ordinance works of a dozen 19th century armies and navies worked on the stuff for a couple decades and never managed to make it in bulk stable enough for mass issue anybody was happy with.
Uh, aren't we talking about cottage manufacture, here? Or did I miss something? I'm not talking about filling 16-inch naval shells with the stuff, after all...

Not to mention that most of the battle is knowing that something is possible. Halfway knowing how it's actually done is even better. I propose that a TL8 high-school chemistry teacher thus benefits on both counts. And then once one person figures it out, word will spread. You just need one smartguy.

And after all, if lead picrate is too complicated for you just remember that mercury fulminate is pretty straightforward chemistry: mercury, nitric acid, and ethanol. It's just a bit too easy to kill yourself while doing it, particularly for an amateur, but in AtE you'll have a good supply of desperate amateurs so losing one on occasion is no great liability. :)

Quote:
Originally Posted by malloyd View Post
Edit: I think the least crazy materials for make your own percussion caps are probably perchlorates. Sodium perchlorate is not too insanely volatile and fairly easy to make from salt and DC current, and if you are making black powder you already have some potassium counterions from somewhere (for the saltpeter) to convert it to something less hygroscopic.
Interesting... I don't think it's been done historically, though, so I can't comment intelligently about the viability of the idea. Potassium chlorate was used, but as a sort of augmentation to other primer compounds, like lead thiocyanate.

EDIT- Wait! I just found a reference that potassium perchlorate was indeed used as a primer compound! So, awesome.

Last edited by acrosome; 05-01-2016 at 08:58 AM.
acrosome is offline   Reply With Quote
Old 05-01-2016, 09:05 AM   #55
evileeyore
Banned
 
evileeyore's Avatar
 
Join Date: Jul 2006
Location: 100 hurricane swamp
Default Re: What kinds of firearms would people start making [After the End]?

Quote:
Originally Posted by Polydamas View Post
I know that house style discourages it, but I strongly wish that S.A. Fisher and Hans had bucked the trend and included short bibliographies in Pyramid 3-88 and HT Adventure Guns.
You could always PM and ask them for a recommended reading list.

And then post said reading list here.
evileeyore is offline   Reply With Quote
Old 05-01-2016, 10:44 AM   #56
Polydamas
 
Join Date: Jan 2006
Location: Central Europe
Default Re: What kinds of firearms would people start making [After the End]?

Quote:
Originally Posted by evileeyore View Post
You could always PM and ask them for a recommended reading list.

And then post said reading list here.
I'm kind of ashamed to ask them for more free help given the amount of money and time they have invested in learning what they know, especially since there is no chance of me running an AtE game. The description in Pyramid 3-88 is just a bit too concise and abstract for me to understand exactly what they mean (for example, how a revolver that could be loaded with either paper cartridges and loose caps or brass-base cartridges would work).

From a setting-design perspective, its worth considering whether you want there to be a lot of edged weapons and hand-to-hand combat or not. If you do, make the most advanced common firearms resemble ones from the 1850s/1860s and earlier; if you don't, you can assume that someone somewhere has solve the propellant-manufacture and brass case problems, or that there are plenty of cases of pre-Fall ammo coming out of caches.
__________________
"It is easier to banish a habit of thought than a piece of knowledge." H. Beam Piper

This forum got less aggravating when I started using the ignore feature
Polydamas is offline   Reply With Quote
Old 05-01-2016, 11:12 AM   #57
evileeyore
Banned
 
evileeyore's Avatar
 
Join Date: Jul 2006
Location: 100 hurricane swamp
Default Re: What kinds of firearms would people start making [After the End]?

Quote:
Originally Posted by Polydamas View Post
I'm kind of ashamed to ask them for more free help given the amount of money and time they have invested in learning what they know, especially since there is no chance of me running an AtE game.
In my experience, most people who know a lot are happy to pass along reading lists so others can also learn. Just ask politely and respectfully.
evileeyore is offline   Reply With Quote
Old 05-01-2016, 11:32 AM   #58
Fred Brackin
 
Join Date: Aug 2007
Default Re: What kinds of firearms would people start making [After the End]?

Quote:
Originally Posted by acrosome View Post
Not to mention that most of the battle is knowing that something is possible. Halfway knowing how it's actually done is even better. .
.....except when the question is surgery. :)

You have to be really careful about "Well, what I do is _hard_ what other people do is much easier" biases.
__________________
Fred Brackin
Fred Brackin is offline   Reply With Quote
Old 05-01-2016, 12:23 PM   #59
Ulzgoroth
 
Join Date: Jul 2008
Default Re: What kinds of firearms would people start making [After the End]?

Quote:
Originally Posted by malloyd View Post
They have a brass cartridge, it's just shallow. The seal is provided by the pressure expanded cylinder of brass pressing against the barrel bridging the breach. It doesn't need to be a very long cylinder to do that.
Ah, great, that makes sense...

The shallow bases might be less of a manufacturing problem than full brass cartridges though.
Quote:
Originally Posted by malloyd View Post
It'll be worse in a normal percussion cap, since one of the major problems is reaction with metals to form even more unstable explosives. In a paper tape it will dry out and crystalize fairly quickly (also bad).
Why is this worse in a percussion cap than in a large explosive shell? A percussion cap/primer is always unstable (though, obviously, being as stable as possible while still working is a virtue). I'd assumed that for a primer you'd be using the crystallized form in the first place, since 'primary explosive' and 'dangerously unstable' are nearly synonymous, though if a wet cap would actually function that might be better.
__________________
I don't know any 3e, so there is no chance that I am talking about 3e rules by accident.
Ulzgoroth is offline   Reply With Quote
Old 05-01-2016, 12:33 PM   #60
Polydamas
 
Join Date: Jan 2006
Location: Central Europe
Default Re: What kinds of firearms would people start making [After the End]?

Quote:
Originally Posted by Fred Brackin View Post
.....except when the question is surgery. :)

You have to be really careful about "Well, what I do is _hard_ what other people do is much easier" biases.
Its also that to many people, things are just not real until they have been showed them and walked through them. Most of the medieval-ish sports armour today has ergonomic and safety flaws which no traditional armour would accept (including armour for sports where people are killed or crippled now and then). Books with photos and descriptions of the real stuff are available in any library, but people often glance at them and then make what their buddies are wearing.

I just had a chat with a man who is finishing his first curie for show fighting with blunt swords. It opens up the sides, and he has put straps over the shoulders and glued them down at both ends, so he struggles to put it on and pull it off over his head. If he had asked me I would have suggested making either the back or the front extra tall, folding it over the shoulders, and buckling it or tying it closed (which was a popular solution in Europe), or running straps over the shoulder and wearing an extra piece to cover the shoulder and upper arm from above (which was popular in China and Japan).

So to copy a technique which they have never seen done, people have to be able to learn from books (hard to represent on a character sheet), and they have to have the training to use them (Chemistry and Engineering, for improvising propellants and primers).
__________________
"It is easier to banish a habit of thought than a piece of knowledge." H. Beam Piper

This forum got less aggravating when I started using the ignore feature

Last edited by Polydamas; 05-01-2016 at 12:44 PM.
Polydamas is offline   Reply With Quote
Reply

Tags
after the end, firearms, tech levels, world building

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 07:40 PM.


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