Logic and homemade cannons

[M. De Land]

I made my first cannon in high school shop class by drilling out a one inch hole in a foot long piece of sold cold rolled steel on the metal lathe. I used spark plugs patched to bore diameter for projectiles.
When making the bowling ball mortar a bit of research was done we found that high pressure oxygen tanks were made of 4140 heat treated steel after being swaged to shape and the nozzle threaded. We decided this would be a good safe tube to use for the mortar we wanted. The idea came from other bowling ball mortar users.
This is high intensity gun barrel quality steel used in modern shotguns and rifles. While quite thin by cannon standards they are still .312 thick in the thinnest part of the wall up barrel and a good bit thicker in the all important breech area.
Our mortar also uses a secondary solid steel cup nested in the breech to carry the full charge so we have a double wall in the firing chamber.
Probably not necessary for strength enhancement but it does seem to make the powder light and burn more efficiently.
A striker mechanism was fabricated to thread into the regulator hole and a musket nipple fit to light the fire.
A 25 foot lanyard is used to pull the striker release lever.
I don't worry as much about a burst barrel as I do about loading after it has been fired.
I wait five minutes between loadings, don't use any wadding and load from a rope ball sling rigged up to keep one out of line with the bore as the ball is lowered.

 

[Darkgael]

My first and only BP mortar....golf ball sized. Called the KISS (for keep it simple stupid) design by Douglas Dickens.


The parts:


breechblock and powder chamber:

 

[Darkgael]

Note about my prior post. I know that it is not a traditional design....I did, however, want to illustrate how a simple, safe, strong design can be fitted together.
The diameter of the breech block is three times the diameter of the powder chamber. The block slips into the barrel and the shoulder on the block mates with a shoulder that has been machined inside the barrel. Two cap screws pull a one inch diameter trunnion against the base of the breechblock, securing the the two shoulders against each other. These parts are further secured by a bolt that screws through the barrel and the breech block into the powder chamber. It also serves as the fuze hole.
Pete

 

[Poor Private]

A feller was killed a couple days ago here in Michigan firing his homemade cannon. Luckily he was the only one injured. People say they heard the explosion 2-3 miles away. Not much on details though. No idea of how it was made, what powder he used, what he used for construction. I wish the news would go into more details instead of being the first with the info, and stop there- no follow up.

 

[Zonie]

A few things found on the net about the Michigan cannon:

Sgt. Gary Wilson, squad leader for the Michigan State Police Hart Post says the homemade cannon was made from a steel pipe about a foot in length and three inches in diameter.
http://fox17online.com/2016/07/04/police-man-killed-in-homemade-cannon-accident-in-newaygo-county/

And this link talks about a woman in Iowa, also killed by an exploding cannon.
http://www.miamiherald.com/news/nation-world/national/article87571072.html

 

[coloradoclyde]

I just heard about the woman in Iowa, and went to post it.....Zonie beat me to it...Didn't know about the one in Michigan.

It's a Solemn reminder that these aren't toys... :shake:

 

[steinauge32]

I built a cannon a few years back from a piece of 3 1\2" OD 1018.It is a one pounder,uses a 1 3\4" ball.The barrel is machined from solid,only thing welded on are the trunnions.I have fired it many times and always use a fuse and get behind the truck.Reason for that is that any cold drawn steel is not really suitable for gun barrel use.No point in taking unnecessary chances.Fortunately I live where I can fire it without endangering anyone else.I made a smaller 1 1\4" bore version out of a piece of 416 stainless and am equally careful with that.If I can figure out how to post pictures on here I will do so.BTW one of the primary artillery rules is to wet swab the bore between shots-seems like a number of people in the cannon disaster thread didnt know that.