Calling black powder cannon experts.

[gordinir8]

I want to build a naval cannon that will use 6.5mm steel balls, question is how bigger than 6.5 my barrel should be?
Thank you

 

[Herbiev]

this site has some great info for smooth barrel cannons

http://arc.id.au/CannonBallistics.html

 

[10K Pete]

6.5 is pretty small and you don't need much windage. For golf balls (1 5/8") I use a 1 3/4" bore for long calibers like 40-50. For shorter calibers
I go a bit smaller. So it's not much percent of bore.

6.5 you can easily patch which works great on a smooth bore.

Pete

 

[golddustpeak]

There is a section on black powder cannons with a lot of knowledge here:

http://www.go2gbo.com/forums/#10

 

[Barnbikes]

My 50cal. (.500") musket uses a .490" patched lead ball.

 

[IceFyre13th]

Generally, the round ball is 0.010" (0.254 mm) smaller than the bore of the barrel.

Patches are approximately 0.010" (0.254 mm) thick and act as the seal between the ball and barrel.

Patches should be lubed with bore butter( http://accessories.tcarms.com/product/natural-lube-1000-plus-bore-butter-2-oz-tube-natural-scent/ ).

 

[gordinir8]

Do you know where i can find those patches and if they are available for such a small caliber?
Also i am not sure if i can order this lube so is there any alternative, is it something like a grease or something?

 

[10K Pete]

Do you know where i can find those patches and if they are available for such a small caliber?
Also i am not sure if i can order this lube so is there any alternative, is it something like a grease or something?

Almost any fabric will work. On larger stuff like a 50 cal I've used old
denim, pillow ticking, shirt flannel, cotton twill. A 'stout' fabric.

On your 6.5 you might try tee shirt material or pajama flannel or similar.

Thickness should be enough to make a snug fit. It doesn't have to be tight.

For grease, Crisco works very well or plain lard. That's pretty much what the 'yellow' product is.

No need to buy stuff you already have in the house!

Pete

 

[gordinir8]

So you mean something like this: http://huntingpa.info/2010/04/making-pre-lubricated-patches-for-shooting-round-balls/
Unfortunately Crisco is not available in Greece either (as many other stuff i need for my crazy ideas) but i am sure i can find a food alternative.
Maybe bore butter is not that hard to order after all. To give you an idea, black powder, fuse or even noise guns are not legal here.
I guess that makes my hobby more interesting.

 

[Barnbikes]

but i am sure i can find a food alternative.

Bacon grease.

 

[barnesrickw]

Silk. Saw that on Last of the Mohicans.

 

[napoleonb]

Remember that balls made of steel instead of lead don't deform that easily.
Most bore sizes and patches are generally speaking chosen for lets say 12 shots worth of fouling, thus decreasing the bore diameter. Lead will deform even when the bore is fouled and keep inserting and shooting safe. Steel on the other hand will create much more pressure when inserted into a foul bore and when fired.

 

[IceFyre13th]

Do you know where i can find those patches and if they are available for such a small caliber?
Also i am not sure if i can order this lube so is there any alternative, is it something like a grease or something?

You can make your own with a round gasket punch and cotton material. Old timers even used paper wasp hive and bacon grease.

I tend to like bore butter with my black powder guns along with pyrodex powder, it helps to keep fouling at bay and easier to clean with hot water. Never use modern gun oils (especially synthetic stuff) with black powder, it will gum up everything. Hot soapy water and an air gun is all you need for cleaning followed up with a lubing of bore butter to keep the rust away.

Also I second the lead ball suggestion above, its easy enough to make your own ball mold and then use a swaging tool to make all the balls the correct size. ( https://en.wikipedia.org/wiki/Swaging ) You can make your own swaging tool as well.

 

[stevehuckss396]

If a cannon barrel were to be machined out of steel, what material should be used? would anything work like 1080 or should a good 4340 be used? Should the barrel be hardened and tempered?

 

[MachineTom]

I don't know what experience you have with firearms. Since you live where they are illegal. A cannon as you describe could fire that ball at least 2KM or more. You best know where you are when you fire that thing.

With cannons a general set of rules is based on the bore. The breech end diameter should be 3 X the bore, the muzzle should be 2 x bore, the trunnions should be about .7-1 x bore in diameter, and 1-1.5 x bore in length.
This is for iron cannons. For bronze you can lean towards the lower end of things.

I've built both Bronze and SS signal Cannons. And follow these ratios, even though you can't fire anything out the bore.

One suggestion to you, DON'T do this.

A shotgun shell as do all gun shells have a primer to set off the powder charge. These small primers (209 Type) are about the bore size you want They could easily mounted in the breech end and give out quite a loud noise when fired. I use them when test the firing mechanism of the cannons when I build them. I fire them in my shop,but for fear of breaking a window, I point the muzzle out the door when they are fired.

 

[retailer]

Back in the 60's while in high school I made the model naval canon that was in a book called The Boy Mechanic, it was available in the school library. Barrel was plain mild steel and the timber carriage was cut from a cheese box I bored it .25" and shot small ball bearings at the back fence, I used an empty .22cal cartridge case as the powder measure and FFF black powder. Not a huge amount power behind the ball bearings and I recall not as powerful as my older brothers air rifle, at a distance of about 25meters the balls left a good dent in soft pine wheras the air rifle would easily pentrate the skin (I still have the pellet in my leg)

 

[gordinir8]

What i have in mind is to penetrate a beer can in a distance of 3-5 meters. What you are describing here is far more from what i want to build and far more from other small size cannons i have seen in videos and there are of a greatest calibre.
My gun will be .25 calibre able to shoot 1/4 steel balls.
I have built the barrel from bronze and shape it so far but haven’t drilled the bore yet since i am not sure if it will be 6mm bore or ¼. Depends of steel ball size availability. I have followed the general set of rules you referring too.
I guess that i can adjust the force of the gun by adjusting the amount of black powder and i am planning to keep it low.
I have also build and fire many times a smaller, 4.3mm bore cannon that is not capable to penetrate a beer can so comparing those two cannons it is hard to believe that it could fire at 2km distance, of course I can’t ignore your words since I am not an expert.
Please I would like to hear your comments

 

[retailer]

Here's a pic, barrel is about 125mm long, been sitting in the garage since we moved here about 35yrs ago, looks like it needs a bit of oil on that rust.

 

[gordinir8]

I think it deserves a little bit of care since this comes from your childhood, spend a couple of hours and it will be fine.