Plausibility check for mixed TL3/4+2 firearm

[Varyon]

Originally Posted by TerryW

B) Once you have nitrated paper you're halfway there to nitrocellulose, aka guncotton, which can be ignited by electric shock.

That's comparable to saying once you have uranium paint you're halfway to a nuclear bomb. Nitrocellulose is markedly more complex than paper soaked in nitrate salts - it calls for a chemical reaction to actually attach nitrate groups to the cellulose molecules, which in turn calls for a mix of rather pure sulfuric and nitric acids. You need high-quality cellulose for this - cotton is ideal. You also need to carefully rinse it, as if you leave excess nitrates on it, it will typically ignite on its own once dry - and in real history, it took about 20 years from someone figuring out the trick of using aqua regia* that mix of acids to getting the kinks worked out so it could be produced without blowing up the factory (near the end of TL 5).

*I misremembered - I thought aqua regia was the term for mixed nitric and sulfuric acid, but it's actually the term for mixed nitric and hydrochloric acid. Oops.

Originally Posted by thrash

The spark discharges directly from the crystal. No wires required, although they can be used to direct the spark somewhere else.

Is quartz (or whatever you use - my original idea involved topaz) resilient enough to survive the sort of contained contact explosion that would result? Assuming you even get an explosion, that is - I'm unconvinced you could get the power required for ignition out of this, but I could be mistaken. Having the quartz in contact with the powder would certainly be interesting, as you'd basically have it being constantly compressed by the pressure and thus producing more electricity. Would that influence the reaction somehow?

EDIT: Also, it seems like it would be difficult to have the quartz - and its striker - electrically isolated from the barrel, yet fixed in place.

[Anders]

Originally Posted by Varyon

That's comparable to saying once you have uranium paint you're halfway to a nuclear bomb. Nitrocellulose is markedly more complex than paper soaked in nitrate salts - it calls for a chemical reaction to actually attach nitrate groups to the cellulose molecules, which in turn calls for a mix of rather pure sulfuric and nitric acids. You need high-quality cellulose for this - cotton is ideal. You also need to carefully rinse it, as if you leave excess nitrates on it, it will typically ignite on its own once dry - and in real history, it took about 20 years from someone figuring out the trick of using aqua regia* that mix of acids to getting the kinks worked out so it could be produced without blowing up the factory (near the end of TL 5).

On the other hand, if you do know how to make it, it's not difficult to make. My dad made some in the cellar of his misspent youth. Grandma was not pleased.

[Varyon]

Originally Posted by Anders

On the other hand, if you do know how to make it, it's not difficult to make. My dad made some in the cellar of his misspent youth. Grandma was not pleased.

I've never been adventurous enough for DIY explosives (or really explosives in general, outside of fireworks). The primary difficulty may be getting the reagents - I previously thought it would be a relatively simple matter to purify the sulfuric acid via reflux distillation, but looking into it further I find that sulfuric acid has an extremely high boiling point - over 300 C - and the glassware at the time may be unable to handle that. If you can manage concentrated sulfuric acid, the method previously linked (saltpeter+sulfuric acid in a reflux still) may be able to produce concentrated nitric acid for you, after which you mix the two together and soak cotton in it (and rinse the cotton well) to produce your guncotton. You'd need to produce the acids during winter in a snowy region, and given they're pretty reactive you'd want to use them pretty quickly, so you may only be able to produce your guncotton during winter.

All told, chances are good you'd be best off just using the available black powder with a flintlock rifle.

[Rupert]

Originally Posted by Varyon

I've never been adventurous enough for DIY explosives (or really explosives in general, outside of fireworks). The primary difficulty may be getting the reagents - I previously thought it would be a relatively simple matter to purify the sulfuric acid via reflux distillation, but looking into it further I find that sulfuric acid has an extremely high boiling point - over 300 C - and the glassware at the time may be unable to handle that.

That just means you boil off everything else, leaving you with mostly sulphuric acid. Then you carefully use that for whatever. Carefully, because just what impurities you've got and what they do could be 'interesting'.

[TerryW]

Based on the skills available to the group, we're better off with the New Inventions process rather than the Raising The Local Tech Level rules. The GM has thrown in a house rule of "Inspiration Points", where the accidental time-travellers can tell a skilled local about the wonderous crafts of Ne-no-kuni* and give advice and guidance to make something similar. What that boils down to is that the PCs will be better as patrons and guides, rather than actual engineers. Assuming we can accumulate enough resources to attract skilled workers.

Based on how long it takes to gather Inspiration Points (After a month of game time we accumulated 1, which allowed a local healer to analyse a bottle of hand sanitizer and invent an antiseptic wash slightly better than the ones already in use), improved firearms are a long way off.

* After our interactions over a month of game time, both with the locals and with the inspectors from the Department of Divinities, people have decided two things about us:

A) We're lost wanderers from a magical realm similar to but wealthier and more powerful than the "real" world,

and

B) We're idiots.

[Ulzgoroth]

Originally Posted by Rupert

That just means you boil off everything else, leaving you with mostly sulphuric acid. Then you carefully use that for whatever. Carefully, because just what impurities you've got and what they do could be 'interesting'.

'Mostly' sulfuric acid, yes, but not really strong stuff.

Per wikipedia prior to the 19th century invention of the contact process concentrations above around 80% could only be achieved by dry distillation of sulfur-bearing minerals. Which is fairly ancient, but excessively costly if large quantities are needed.

[Anders]

Originally Posted by Varyon

I've never been adventurous enough for DIY explosives (or really explosives in general, outside of fireworks).

My dad was pretty wild as a youth. He and his friends almost shot down a plane with a homemade "pipe"-rocket.