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Discussion Starter · #1 ·
I've always wanted a cannon and recently built my own. I did enough research to believe I've done a good job with design and construction. I'm a professional mechanic, experienced fabricator/welder and have been shooting conventional firearms for many years.
I decided on a 2 1/4 inch bore because I have a good supply of billiard balls and found an 18 inch piece of seamless 3/4 wall tube in that size. I had my local machine shop build me a powder chamber/breach plug that I press fit and welded. I copied the powder chamber design from coaches club and did some testing to ensure it could hold 2 1/2 ounces of powder and some wad.
I appreciate any one who's still reading.
I've never seen a cannon fired besides a few blank rounds at reenactments. I've scoured YouTube and found it lacking on any real info. My actual question is what kind of trajectory and accuracy can I expect? With about a foot of barrel left after the plug, coaches club says they saw 1100 fps from a very similar design. Any info, suggestions, tips, things to avoid appreciated.
 

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What is your wall thickness? 3/4"? Or does your chamber have a reduced inside diameter? The reason I ask is that widely accepted safety standards require wall thickness over & behind the chamber be equal to the bore diameter. So a cannon with a 2.25" bore should have an OD of 6.75. With a reduced chamber like a mortar or howitzer... say 1.5"... would have an OD of 4.5". You cannon could be built up further over the chamber like Parrots were.
Links to these recommended standards by National Cannon firing organizations are linked in our stickies: http://www.go2gbo.com/forums/blackp...ruction-new-cannon-builders-design-standards/
We take cannon safety very seriously. Accidents threaten the hobby we all love.
 

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Discussion Starter · #4 ·
My powder chamber is 1 3/16 x 4 1/2 making the wall thickness at the chamber about the same as the chamber diameter. I tried to post pictures but my hd phone camera has too large of an image so I will have to figure out how to lower resolution.
 

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In some ways I understand your desire to make your own barrel. Until you realize the physics, and forces involved in even scale artillery, I recommend you buy a barrel made by a maker, and put yourself "to school" to see if you want to attempt (even) making a carriage. A hobby bore of 2 1/4 inches is no small matter....
This is not a matter of making a "larger bore" firearm.
Reading must include a catalog from South Bend Replicas, The Complete Cannoneer, and works by Ian Hogg, and Adm. John Dahlgren. Atillery's history is plagued with crewman death, as a result of gun failure. What people will tell you here, is risking injury or death to engage in this hobby is not acceptable! Do your research and be safe! Welcome to our history and knowledge rich pastime! :D
 

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Discussion Starter · #8 ·
My desire to build my own barrel was based mostly on budget. I have about $250 into the cannon and carriage. Frankly it was the only way I was going to have one. I'll order a copy of the complete cannoneer and have time to read it before I get a chance to shoot it. It's hunting season here and I try to avoid making too much noise in the woods where hunters may be in the area. And I don't know how much noise this thing is going to make.
 

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Near as I can see, your wall thickness surrounding the powder chamber is pretty close to an inch, 2.25"-1.18"/2) +0.5"=1.04". Since you are using steel rather than cast iron this may well be close enough to powder chamber diameter. Your design reminds me strongly of a field howitzer where a reduced powder chamber diameter is paired with a much larger bore to decrease weight. Of more concern to me is the roughness of the powder chamber walls (could trap sparks) and whether you were able to seal the seam around the chamber's front edge to prevent the forcing of corrosion producing residue between the chamber plug and the barrel.
My other concern is your carriage. As is, the welds to the base will almost certainly break with very few firings sending the barrel flying. Please consider reinforcing these points or rebuilding the carriage with stronger material than reinforcing rod.
2.5oz of powder may be more than you want to use, try much lower loads first. Wadding is a very bad idea, see the cannon accident thread currently running on the forum. Foil wrapped powder charges made to fit your chamber will make your life easier and safer. Accuracy at any distance isn't going to happen with this short a barrel so large charges would be wasted and yeah it will be loud.
Please don't consider the advise/suggestions here as criticism, we're all interested in you having a good experience and a safe one. Best, Pete
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Im by no means an expert around here, im still in process of buying my first cannon and i know how that budget thing works too.

I did wonder about the use of rebar, it bends pretty easy. But you will know if that happens after a few shots.

Now to throw some positive in for you. It looks really nice. Is there a cascabel knob/ball behind the chamber? If not weld a trailer hitch ball back there for a finishing touch.

The rest of these guys can help you stay safe.

It looks like fine work though, and i like it.
 

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Discussion Starter · #12 ·
If I was easily offended by criticism or advice I wouldn't have joined this forum and started asking questions. I appreciate everyone's concern for my safety and I don't want to make you all look bad either. As for Pete's concern about the powder chamber roughness, it was simply drilled and not bored or finished, but the picture looks worse than it is and I will diligently scrub and give it a few minutes between firings. The breach end of the barrel was bored out about 1/8 to give a finished area and a solid face for the plug/chamber to fit into. The interference between the barrel and plug is 0.003. I heated the barrel to about 400 and the plug slid in with little persuasion. As far as the seal on the front I was also concerned about the possibility of corrosion but had no good idea on what to do about that. With the tight fit my machinist assured me any water entry was highly unlikely. The carriage is sturdier than it looks, I also had my doubts about using rebar. I may add some more plate around the joints.
 

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Discussion Starter · #15 ·
Near as I can see, your wall thickness surrounding the powder chamber is pretty close to an inch, 2.25"-1.18"/2) +0.5"=1.04". Since you are using steel rather than cast iron this may well be close enough to powder chamber diameter.

Pete, it is 2.25-1.18/2 + .75=1.29, making the wall thickness slightly over chamber dia.
 

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Your barrel is great. Think a while about a carriage made of metal, wood or both that has enough mass to dampen recoil. That will aid accuracy. Attaching the barrel to the carriage in a conventional manner will help also. The way that you adjust elevation will keep the shot from going wild. There are many sighting systems.
 

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Discussion Starter · #19 ·
I again copied coaches cannons on the mounting system, it is not shown in the pictures but there are straps that lock the trunions into position. I made the carriage light intentionally, for ease of transport, but long enough that it will not flip over when fired as I have seen many times on you tube even on coaches carriages. Sorry to mention them so much since they are not a sponsor. I also considered that allowing it to roll straight back, without much weight would lessen recoil damage to the carriage. I trust your experience and will consider a heavier carriage if that will improve accuracy. Thank you and everyone for the support.
 

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Discussion Starter · #20 ·
I found the accident article about the summer camp counselor that was killed. It stated as was suggested earlier that a gap between powder and projectile can be very dangerous. With my powder chamber only a max load will completely fill the chamber, and the projectile will still not be firmly seated against the powder. Do I pack this gap with a filler? Flour? Sand? Paper? Starting with a half load will leave about 2" of space in the chamber. This was not something I had previously considered, as the design was copied from a commercial manufacturer that simply shows putting in the desired amount of powder, then the ball, and firing. Is this only a problem if the powder is packed with a wad inside the chamber?
 
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