Making a cannon

[Titus]

Is there anyone here who has, or know of someone who has built a cannon? I am not talking about the clever people who take a piece of iron pipe and just plugging it at one end. :shake: I am talking about turning a billet of steel on a lathe with proper bore wall dimensions.

I am looking into building a proper scale model Napoleon III cannon of a maximum 1" bore which is the maximum caliber allowed by the South African Firearms Control Act for a hobby cannoneer. Barrel length will be no more than 500mm

What type of steel is strong enough (yet turnable on a lathe) for maximum powder charges 300grains of FFg? And where will I be able to find reputable cannon building plans and dimensions on the internet?

 

[crgabel]

I have done 4 cannons so far and have used 4140 for my material. On my Mortar which is 101 mm bore i held a 25mm wall thickness per side just to be sure. I'm using 300gr for patched softball and 600gr for blanks (wad of newspaper)
On my golfball navel i have 19mm wall thickness and shoot 90gr od FF with a patched golfball and 300gr for blanks.
As for the drawings sorry have not looked for such documentation on other cannons.
Craig

 

[crgabel]

 

[Titus]

thanks crgabel, BTW, how mush does that mortar weigh?

 

[54mountain]

I built a 1" bore (20mm) swivel gun and used 4140 the bore is 18in from muzzle to touch hole with a solid breech a good rule of thumb is to keep the wall at the breech as thick as the bore. I shoot 300gr 2ff in mine as a standard load with no problem.
Oh I forgot to mention that I left about 3in of steel behind the bore.

 

[GunneyG]

The following link will take you to a series of pages showing the construction of a Royal Navy pattern 24 pounder of 1779. It has reached the completion of the barrel stage but the carriage has yet to be completed.

AISI 1018 is more than adequate for muzzle loading cannon making. I don't know what steel naming convention is used in SA but 1018 is a mild steel typically cold finished. AISI 4140 is a low alloy chrome molybdenum steel, frequently used for rifle barrels.

 

[crgabel]

It weighs in at about 120 lbs or 55kg. That is why i did the handle with the wheels. I'm not getting any younger, and the wife won't help drag it out onto the lawn.

Craig

 

[crgabel]

Gunney,
I agree 100% on the 1018. I have used that on some of my handgonnes. But for the Mortar, the company i work for just happened to have the material in stock and i got it at a good price.
Craig

 

[CU_Cannon]

Here is a pic of the 12pdr coehorn mortar that I built. It is a slightly scaled down version of the 24 pdr.

It is turned from solid 1018 steel. I would personally avoid 4140 unless you can weld it properly. With out proper preheating and cooling hard spots can form in the weld area.

 

[CU_Cannon]

Do a search for “buck sticks”. The cannon information isn’t bad. Other sections have to be taken with a grain of salt.

 

[Will Bison]

Hey Titus;

Tie up with the SA miniature cannon club. A lot of good folks that have built some neat guns. They shoot once a month.

I,m trying to think of who I know in or near Pretoria. Let me think for a day or so and I think I can come up with a contact.

I'll make another post or send you an e-mail.

Bill

 

[Titus]

Thanks for all the info guys. :hatsoff:

 

[Will Bison]

Titus;

Head an an email to Douglas B Dickens [email protected] He is in the Durban area South of you. He shoots with the SA cannon club.

Very sharp guy on cannons and may be able to tie you in with some local folks in Pretoria.

Bill

 

[Titus]

Thanks Bill! :hatsoff:

 

[Will Bison]

Titus;

I forgot to include Dougs web site[url] http://doubledgopherranch.mysite.com/[/url] Let me post that and make sure the link works.

 

[Titus]

Got a quote today on AISI 1018. In our convention its EN8 steel. A billet 700mm long and 90mm in dia will cost me a mere R350 (US$50). I reckon that'll make a pretty good sized replica barrel. :thumbsup:

 

[Titus]

just got a better quote! :hatsoff: :hatsoff: R290.40 for the same piece of steel, that equates to roughly US$39.51. Weighs in at a hefty 36kgs. :hmm: Reckon it'll be much lighter after its been to the lathe for some streamlining. :winking: :haha:

 

[mike alexandre]

Do it in bronze, you wont regret it.

 

[Will Bison]

Sounds like a resonable price for a 90mm billet and if you go with a 20mm (+ or _)bore it will allow a good wall thickness for mounting the trunnions. :thumbsup: :thumbsup:

Bill

 

[Scota4570]

Having just completed a mortar I have some observations. Mild steel works great on the lathe. The alloy I used , possibly 4140, was horrible. The tube is now 2.6" ID. It started as 2 3/8". The interior was rough and irregular. One pass with the boring bar took 45 min. Carbide tools were necessary. If I broke a high speed tool halfway through a boring pass, that would have been very bad.

IF I was buying new steel I would have used leaded soft stock . This is the stuff most black powder barrels are made of. It is a dream to machine. The extra strength of the 4140 is totally irrelevent at these pressures. I only use high alloy steel because I bought it by the pound at a good price. If I did it again I would use DOM mild steel or lead alloy.