Thread: legaly speaking....... mini canons?

Spud guns are a firearm, no worries there as long as it is 762mm+, not sure around the legalities of making firearms though.

Originally Posted by Tussock

A cat licence for a spud gun.

I neeeed a cannon.

Tussock

If you or a mate has access to a Lathe and know how to operate it then Make one.

There's nothing special to know if you apply these general rules.

You need to use a good grade of steel for the barrel, mines made out of 4140.

The powder chamber needs to be 1/3 the outside diameter of the barrel in all directions.
My powder chamber is 1" in diameter the barrel is 3" in diameter and theres 2" solid steel behind the barrel with a steel tow ball welded on as the cassabell.

The muzzel outside diameter should be large enough to have at least 3/8" wall thickness remaining after a taper has been applied to the barrel... more is better.

The barrel length can be as short as 2.5 times the diameter of the projectile .... this would be a Mortar or as long as you like within reason.

The projectile diameter must be 39/40ths of the bore diameter to allow for windage when firing.

If the powder chamber is smaller than the bore diameter then the cannon is called a Howitzer.

Ensure the powder chamber is large enough to hold sufficient Black Powder to fire the projectiles of choice, my powder chamber holds 350gr FFg

Use only FFg, Fg or Cannon grade black powder. anything else will see your cannon turn into a pipe bomb.

There's lots more info on the net if your keen.

Cheers
Pete

Youtube has excellent oxygen bottle ( welding type) cannons that fire bowling balls.

High pressure pipe used in hydraulic rams are probably strong enough , you can shrink reinforcing pipe over the breach area if needed . If you can get some , railway waggon axles are supurb steel , bore them out for a morter

That would be nice and smooth and round and constant diameter being ground.
Shed 80 pipe could be another option.

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Originally Posted by veitnamcam

That would be nice and smooth and round and constant diameter being ground.
Shed 80 pipe could be another option.

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Remember Welded Pipe of any sort is no good.

It will split.

Cheers
Pete

Originally Posted by P38

Remember Welded Pipe of any sort is no good.

It will split.

Cheers
Pete

Shed pipe is seamless. Used in high pressure steam,flammable,toxic etc.

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Yep shed pipe is seamless, I use shed 40 for mine but I only get to a max of about 1500 psi

Originally Posted by veitnamcam

Shed pipe is seamless. Used in high pressure steam,flammable,toxic etc.

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Yes I know, some people reading this may not and may end up using any old pipe.

Plug Welding the chamber when using Seamless pipe is critical and will create a weak pont in your cannon ...

One thing you dont want is your cannon going at both ends at once.

Cheers
Pete

oooh I might have a length of stainless pipe came off a sonar, wonder if that would be strong enough.

@spanners think I read somewhere anything over 20mm is a canon...cant remember where off hand.

So my tiger tank's 88mm is fine then....



(kidding)

you guys are insane....