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Thread: brass cannon
07-21-2010, 06:21 AM #1
A guy at work wants me to make him a brass cannon, black powder
1 1/2 inch across the flats of a bar of hex free machining brass
I'm concerned about wall thickness...............
kinda important.............any suggestions.............Mikey
07-21-2010, 06:43 AM #2
I wouldn't make it any larger than .50" bore and leave the same for wall thickness. You might be able to go larger but why risk it? How will the trunnions be attached?
07-21-2010, 08:28 AM #3
If your friend wants to shoot paper wads and use the gun for a noise maker, the dimensions above would work pretty well. If he wants to shoot projectiles, I don't believe I would use brass.
If anyone here decides to attempt to size the barrel for you, they must use the thick wall pressure vessel equations. The more simple thin wall equation, [stress]=[Pressure][outer radius]/[wall thickness], is flat out incorrect for this problem.
Identifying the specific alloy is also important to get a sensible answer.
[Work like this is my technical specialty.]
07-21-2010, 09:03 AM #4
brass cannon maybe not
guys thanks for the quick replys
i always worry about someone who plays with gun powder
with no experence.........I might rethink this project
Thanks again ........Mikey
07-21-2010, 10:45 AM #5
Wise to reconsider if its a shooter.
With a free machining alloy there is a good chance the tensile strength in the hoop is much lower than the tensile strength in the axial direction.
07-21-2010, 10:59 AM #6
In your reconsideration you could reference the 1862 Ordnance Manual which clearly gives the constituents of the "yellow" metal used for ordnance. This was a tough bronze containing 90% Copper and 10 % Tin - hardly anything like brass.
07-21-2010, 04:58 PM #7
"The more simple thin wall equation, ... is flat out incorrect for this problem."
Only solution then, is to thin out the wall!
07-21-2010, 05:19 PM #8
Build the cannon any way he wants but DO NOT drill the hole for the fuse. Let him do that, which can be done easily with a proper sized bit and a hand dill. That way, you didn't make a cannon, you made a model, your customer turned it into a cannon.
07-21-2010, 05:22 PM #9
07-21-2010, 08:13 PM #10
I would have no problem making a brass barrel cannon for my own use as it would always be under my control, too.
Historically, brass barrel rifles and pistols from the flint era are not unknown, but I wouldn't say they are terribly common, either. Cast bronze cannons are common. But, there was a better way.
Olin has a nice brochure available that discusses the uses and properties of Alloy 260 cartridge brass (much more than cartridge cases), including mechanical properties for different conditions of work hardening. A search for "Olin alloy 260" will turn up a link, or: Olin Brass Corporation will get you there.
Kansas Cannon Works makes some very nice small cannons from steel bar stock that I think are a good value.
Kansas Cannon Works Cannon Page One
I have a one inch bore Napoleon. Wish I had a golf ball barrel since projectiles are cheaper.
07-23-2010, 06:22 AM #11
brass cannon not
Thanks for the input, I told him about your input, he said he wants a noise maker
I don't think I need the grief from someone that thinks it is a toy
less and less interested in this thing.
07-23-2010, 08:26 PM #12
Sooner or later someone WILL try shooting projectiles out of it. I am reminded of the story about a Scout Master who used something like 2 pounds of black powder in a smallish cannon for firing salutes with his troop standing around. Could have blown up!!
07-24-2010, 06:24 AM #13
Do be careful out there.
07-24-2010, 07:29 AM #14
The problem goes beyond over charges of black powder.
Non-shooters don't know the difference - a pile of smokeless powder is black, and a pile of black powder is black. Many shooters don't know the difference, either.
The first owner of the cannon might be knowledgable. What about the next owner? Last week end I found a neat cannon on a field carriage at a garage sale, complete with touch hole and stories from the original owner's children that it was shot. Thing is, there is something that is not right about the barrel on that gun, it's not carbon steel, I'm over 90% certain it's a stainless material - it has scattered rust along with clear patches free of rust, and near as I could tell it has been stored in the garage without climate control. I passed, although the price was right for the carriage alone. The point is, I don't know the cannon's background without doubt, so the risk is beyond my range of tolerance.
The photo above is one consequence. The KA frat at the University of Missouri - Rolla killed a student with a cannon blow up about 1978. That's not the only example, either.
07-24-2010, 08:47 AM #15
07-26-2010, 07:29 PM #16
Probably the best thing for a noise maker is a thunder mug. These are thick walled short muzzle loading devices that are fired vertically. For example, 3" diameter, 1" bore, 12" overall length, 10" bore length. They usually have a handle for easy carrying. And they are not readily converted to launching projectiles.
Here is a video: thunder mug video