I've just made a batch of guncotton with potassium nitrate

>>1048039
Pretty sure they use a drill, anon, maybe an end mill. But if your main concern is how to make the touchhole and not "how do I keep from blowing my ass into 5.23x10^11 pieces," you may want to think about the whole scheme a little bit more.

>>1048047

I think its safe.

Firstly, guncotton is very weak and the cannon is very small.

Secondly, I'll obviously duck behind a hillock or something before it goes off.

The risk to me is minimal - its just it would be annoying if the cannon broke

>>1048052
>guncotton is very weak
'kay.

>>1048055

Relative to other explosives. And obviously because I'm not a complete idiot I'll start with tiny amounts of guncotton and slowly increase propellant amount as I go.

>>1048039
don't use pipe. its brittle and will fragment. thats why pipe bombs are made out of pipe. you want a nice springy steel.

>I think its safe.

>>1048056
>And obviously because I'm not a complete idiot I'll start with tiny amounts of guncotton and slowly increase propellant amount as I go.

thats a great way to get a sudden and unexpected fatigue failure. don't nigger rig shit like this if you value your life.

>>1048075

i have literally made cardboard cannons using guncotton that worked fine

im confident even a scrap pipe can handle the use i plan for it

>>1048077

oh. what kind of testing system would you suggest then?

>I usually work in theoretical Physics
Experimentalist here. The joke goes that the experiment always breaks when the theorists come to visit. But seriously, theorists tend to have trouble with real world things.

>>1048039

You can get a 1/3 scale howitzer for 300$ in the US.

>>1048093

but where would be the fun and learning in that?

its a pet project, nothing too serious.

>>1048083
You're not going to get any suggestions on testing your contraption from anyone competent due to liability, OP. That being said, gun cotton is more powerful than black powder, so test it as if it were modern smokeless powder. Iirc most modern ammo runs about 60,000 psi when fired, so if you double that for testing purposes you might be safe. Post pics!

>>1048039
>guys how the fug does cannon work how do i light cannon????
Americlaps, everyone.

>>1048100

I'm english, actually.

not that it matters.

>>1048056
Too light a load can supposedly cause detonation, at least with modern powder. I don't know if your propellant/explosive will cause that our not, so if you do this be very careful with the use of "tiny amounts." Pipe would be the worst for this, even "seamless pipe" has a seam.

File: 43.jpg (624KB, 1024x768px) Image search: [Google]

624KB, 1024x768px

>>1048083
>i have literally made cardboard cannons using guncotton that worked fine

then stick to cardboard. its not about preventing something from going wrong, its about preventing you from dying when it does.

cardboard is safer than shards of pipe metal. a more springy steel won't separate into jagged pieces, it will plastically deform like pic related. its why old school cannons are made out of bronze.

>>1048039
You can find plenty of cannon info in the internet. Some of my buds like to fire bowling balls at the range. Learn to Google blackpowder cannon etc.

A smaller machining project:

https://www.reddit.com/r/DIY/comments/3bedxi/77_picture_stepbystep_fabricating_a_75_caliber/

>>1048118

hm. my mates will let me into the engineering labs, I could probably make mine in a lathe like he did

thanks bruh

>>1048111
Trips aside, while old school cannons were made of bronze, it was more of a luck of the draw kind of thing. Yes, it deforms more plastically, but it was used more because of the 1000°F melting point difference, and the fact that the first cannon barrels were cast by bell makers, who were only people at the time with enough experience to cast something the size and shape of a cannon barrel. And they used a lot of bronze.

Challenge of our age

>>1049515
Why are you spamming the board? What the fuck man. Are we being raided?

>>1048056
Nitrocellulose is not like black powder. It's a high explosive like nitroglycerine and can detonate. Smokeless powder has to be formed carefully and set off under the correct conditions to ensure that it will deflagrate instead, hence things like cordite (combining petroleum jelly and nitrocellulose of known quality into rods of fixed diameter) before modern granular "powder" (essentially, grains of fixed mass and surface area, with various additives).

Also: without careful and competent chemistry, the nitration of your nitrocellulose will be unpredictable. This means basically that the fuel/oxygen ratio, and therefore explosiveness, will be unknown.

https://www.youtube.com/watch?v=WD6vURwCkNA
Skip to the end for a comparison between black "gun" powder and nitrocellulose.