Handgonne Design Questions

[jaxenro]

Hi
I was thinking of having a handgonne made to my design based on a existing 14th century original, not an exact copy but close, from the correct brass/bronze material used for small scale cannon barrels.

Questions:

1. My plan was a .500 bore size 8" long to allow the use if readily available .490 balls and a patch does this sound valid?

2. Is it common to use any type of reduced diameter powder chamber or would a bore diameter chamber be ok?

3. I was going with a 3/4" socket 2" long. With a 12" overall length this gives a solid 2" between bore and docket is this enough?

4. I was going with a 1 1/2" diameter at the powder chamber this gives me a 1/2" wall is this good?

 

[Tinker2]

Questions:

:1. My plan was a .500 bore size 8" long to allow the use if readily available .490 balls and a patch does this sound valid?”

Yes

“2. Is it common to use any type of reduced diameter powder chamber or would a bore diameter chamber be ok?”

Seen both.

3. I was going with a 3/4" socket 2" long. With a 12" overall length this gives a solid 2" between bore and docket is this enough?

More than I have had done on mine

4. I was going with a 1 1/2" diameter at the powder chamber this gives me a 1/2" wall is this good?

” from the correct brass/bronze material”

Talk to freekforge on this sight



William Alexander

 

[jaxenro]

5. What size would you make the touch hole?

Thanks for your answers

 

[Tinker2]

Talk to freekforge on this sight, he makes some.

I would start with 1/16.
I had them drilled at an angle so whatever blast comes out the touch hole was away from me.
Angled toward the muzzle


I also had the socket cut to a #3 Morse taper; it stays on the handle tight and easily removed





William Alexander

 

[jaxenro]

That's a good tip on angling the touchhole thank you

 

[freekforge]

all of tinker2's answers are correct. you really dont need the 2" but it wont hurt anything if you keep that measurement.

i do most of my vents 1/8" but how you plan on igniting the gonne: quill, loose powder, fuse etc. can dictate the vent diameter.

 

[jaxenro]

I was thinking loose powder might be the most historically accurate. I know historically they often used powder chambers but I was going without one for ease this time.

The company making this makes blackpowder cannon barrels up to .69 caliber so they have experience making safe, quality, barrels of this general type.

I am also looking for pictures of tillers but I understand no originals survived? I was thinking of a simple 1" dowel, walnut or cherry, with one end cut to fit the socket and the other rounded over. Or should I use oak? Do we know what is more accurate historically?

I am trying for a simple, clean looking design slightly overbuilt for safety.

 

[Tinker2]

I am also looking for pictures of tillers but I understand no originals survived? I was thinking of a simple 1" dowel, walnut or cherry, with one end cut to fit the socket and the other rounded over. Or should I use oak? Do we know what is more accurate historically?

I am trying for a simple, clean looking design slightly overbuilt for safety.

Shovel handles works for me



William Alexander

 

[jaxenro]

We are using 360 brass specs are here:
http://www.speedymetals.com/information/Material13.html

 

[Tinker2]

We are using 360 brass

Well, I am not a metallurgist so I can’t tell you anything about the 360 brass and I have not made one of brass, so I don’t know.

All of what I had made were of 12L14

I think someone here has made some of brass

I am looking forward to seeing what you come up with.




William Alexander

 

[Zonie]

360 brass comes in several different "tempers" and it is important to know exactly what the material a person has in hand really is.

For instance, 360 in the annealed condition the numbers shown in the reference are close to what I see in my information.

If the stock is in the "half-hard" condition its tensile strength increases but its elongation is reduced to 18%.

In the "hard" condition although the tensile strength is again raised the elongation is so low my information doesn't list the value.

This is very important when making a firearm because the low elongation is an indication of the material being brittle. The lower the elongation the more brittle (and subject to rupture) the material is.

 

[jaxenro]

As I mentioned they make quite a few small scale cannon barrels from firecracker size to .69 or .75 caliber so they have done this successfully many times. I am also following the cannon rule of wall thickness at the breach equaling bore diameter do I think I am good there.

I also asked to make a slightly smaller diameter version of just the socket portion to use as a cap at the other end of the tiller to finish it off, add some protection to the wood, and work as a counter balance. I don't remember seeing his before but plenty of spears had butt caps historically.

I wouldn't be surprised if this works out that they add this to their product line but I can't say for sure. I don't have any connection with them except ordering this gonne

 

[Millermpls]

FreekForge made me a great gonne in steel, 20 gauge (for common supplies, both ball and shot). I still need to make a grip for it. Now that the weather is turning, I hope to get it out to the club for a test drive.

 

[jaxenro]

Was thinking about the stock is so long in the pics wonder if it makes loading easier? Seems like about 4' overl would bring it to a good height