First Cannon

[acoop101]

I am a in college and I just gained access to the machine shop here at school. last week I made 2 cannon barrels from scrap hot rolled steel that the school was going to recycle. Is this a decent material for a cannon? The first one is a .25 inch bore cannon made from .75 inch stock, the other is a 3/8 inch bore made from 1.25 inch material. I will post pics when I have them, but my question is how to mount these without welding to them, I don't want to do this because of the heat effected zone that makes the metal significantly weaker. Any ideas and recommendations would be much appreciated.
Thanks in advice
acoop101 

[Rickk]

When I made trunnions for my nano-cannon I drilled tight, shallow pilot holes, pressed them in, and then brazed them in place with an oxy-acet torch.

[Cat Whisperer]

...
. Any ideas and recommendations would be much appreciated.
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acoop101 

acoop101  - WELCOME to the board!

Do a SEARCH on this forum on trunnions and you will find many threads addressing just that issue.  Lots of good discussion and pictures of how folks here have addressed one of the thorny issues of making cannons/mortars.

Good advice from Rickk.  If you look through what's been posted you will find more.

Mild steel is generally good, taking into account that proper design, building practices and loading techniques are part of the equation.

Here's one of the "sticky's":  http://www.gboreloaded.com/forums/index.php?topic=89682.0  -  try starting your reading here. 

[acoop101]

Has anyone made small scale cannons from Hex stock, what would be a safe side stock side for a 50 caliber cannon?

[CU_Cannon]

The general rule is that you should have one caliber thickness of metal around the breach.  In other words you would want 1.5” stock for a 50 cal cannon.  I think I’ve seen some cannons from hex stock.  They don’t look quite right to me.  I like the more accurate look.  You might look into building a handgonne.  They came in many shapes and sizes.  They only take a couple of hours to build.  I have seen several that are either hex or octagonal.  Do a search for handgonnes and you will get lots of info.

Welcome to the board. 

We need to see some pictures of smoke and fire.

[GGaskill]

For some reason probably related to hand forging, early gun barrels were octagonal rather than hexagonal.  Take a look at Don Krag's post for a cannon with a partially octagon barrel. 

There's no reason you couldn't make a freelance barrel from hex stock but to make it hex the full length, you would have to do the taper on a milling machine instead of a lathe.  Or you could do the chamber area in hex and then a round taper the rest of the length.  Or if you really like flats, you could do a dodecagon (12 sides.)

[acoop101]

I finally have a picture of my two new cannons, the smaller one is a .25 caliber made from .75 hot rolled steel and the other is a 3/8 made from 1 1/4 inch stock, they are both short (4 inches) because here at school we don't have long bits in these sizes and I don't have the money right now to buy them from McMaster. ANY way I have not cut a tapper on the barrels yet just because I wanted to test them before I go removing too much material. I hope to get out and go shoot it some time this week.