Will This Work For a Cannon Barrel?

[XxLT250RxX]

A guy brought this to me wanting to make a cannon barrel from it.  Anyone know what it is and would it work for a cannon barrel?  I has an outside diameter of 3 inches.  The walls are approximately .5 thick and it about 4 feet long. 

[Artilleryman]

Don't know exactly what it is, but it sure has a fast twist to the rifling.

[Ex 49'er]

Could it be from a 40mm?

[Victor3]

 With the fast twist, I'm wondering what kind of practical muzzle-loading projectile could be designed for it that wouldn't strip out of the rifling.

 It might be better used for a breech-loading design (?)

[cannonmn]

So it has about a 2" bore.

The most important thing is to identify the kind of metal it is made out of, and the particular alloy of that metal.  If it is any kind of modern steel, it probably could be made into a cannon barrel to handle light charges, along the lines of the bowling ball mortars made of thin compressed gas cylinders.  I think the internal spline or whatever it is might have to be bored out, don't think that will be helpful to a beginning shooter.

[Tropico]

I am no machinist ., but here it goes.   No.
Isnt  the whole idea of this a bit of a stretch as the 1 caliber rule would imply ? Personally I would think the time and money to end up with a thinner piece of material would be wasteful. After boring the rifling out of it., it wouldnt even be much of a liner.  Myself I would use something differant....,  say a piece o round bar ., Depending on the stock I aquired my bore would then be dictated for me. Unless of course I had a certain bore in mind ., then of course triple that and save up or it. Better to be safe then to experiment.

[dan610324]

my guess is that its some kind of pipeline tubing , I know that similar things are used to have an better flow when you have extremely large volumes of oil for example going through an pipeline .
as it is approximately one full twist in eight inches I cant understand what use it would do in an two inch caliber cannon , I would say its much to fast twist even for an breachloading gun .
and in my opinion the walls are much to thin for use in anything , except maybe an reduced chamber cannon . for example an mountain howitzer , with an chamber of maximun 3/4" diameter

but then you will have another large problem instead .
HOW TO ATTACH THE TRUNIONS IN AN SAFE STRONG WAY ??
maybe you could produce an outer reinforcement cylinder half the length of the finished barrel with an wall thickness of minimum one full inch to shrinkfit to the outside of that tube , then you can machine the holes for the trunnions and put them in place and weld them before you finish the inside diameter of that reinforcement . but this takes a lot of mechanical skills to do , and of course high quality equipment .
but doing it this way you dont need any reduced powder chamber .

be sure you read some old posts here first on breach plug design before you starting this project .

but to be honest I would start looking for another piece of steel for my first cannon  
must be possible to find an solid rod in an junkyard thats makes an easier to build first cannon .

but if you still by any reason want to use this tube please ask here at the forum for advice , we are many here who will help you explaining how and why things are to be made as they are .

please remember that an cannon in this or any size is  NOT AN TOY  its an deadly weapon and can be an even more deadly pipe bomb if its not produced and used in the correct way .

please let us know more about yourself and your plans and we will do our best to help you to produce an cannon who are safe to use . we dont want to read about you in the newspaper .

what experiance do you have in using an lathe ??
what welding experiance do you have ??
what machines do you have access to ??

please always remember my words  "BETTER SAFE THEN SORRY"

[Double D]

If you can determine if this is a gun barrel it might make a good barrel liner, if you can clean it up.  The U.S 40mm was gain twist going from 1 in 45 to 1 in 30 twist. 

Using the measurment you give 3 inch OD, .5 walls leaves a 2 inch bore.  So search for 2 inch bore rifle artillery.  To convert to metric I use Josh Madison little desktop concersion program http://joshmadison.com/article/convert-for-windows  and 2 inch bore is 50.8.  57 mm would be 2.24 bore.

[dan610324]

if you look at the bore diameter in the photo and look at the approximately same distance into the barrel you approximately have 1/4 twist , that mean an full twist in 8 inches , ok maybe 10 inches , but thats way to much in any cannon of that caliber . especially an muzzle loading cannon .
would be very interesting to hear from Mike and tracy in this subject . as they are what I know of the most experianced in this area .

[XxLT250RxX]

please let us know more about yourself and your plans and we will do our best to help you to produce an cannon who are safe to use . we dont want to read about you in the newspaper .

what experiance do you have in using an lathe ??
what welding experiance do you have ??
what machines do you have access to ??

please always remember my words  "BETTER SAFE THEN SORRY"

Thank you for your concern.  As I said this was brought to me by a guy who wanted me to help him turn it into a cannon.  It was my opinion it was to thin.  I told him about this board and told him I would post it here and seek advise from people with much more experience with cannons than myself.   As for my experience and the equipment I have access to, I am a machinist with years of experience and access to pretty much anything I need to complete it.  As for my welding skills, I have had no formal training.  I have a Lincoln stick, Lincoln MIG and an oxygen acetylene torch but my skills with them are self taught and not that great.  

If you can determine if this is a gun barrel it might make a good barrel liner,

This is something I will look into. It may not be possible to determine the origin of it. Thanks

[dan610324]

nice to hear that you told him its to thin , hope he can find an piece of round bar to make an cannon from instead .

but remember the basics
one caliber thickness in the chamber area
preferably half caliber wall thicness in muzzle area
trunnions approximately same diameter as the caliber
try to have the bottom of the chamber as close to an full radius as you can by reshaping
the 118 degree angle in front of the drillbit .
its a bit difficult to do by hand without any advanced tool sharpening grinders , but it can be done if you are extremely careful . start making an perfect template from an 1/8 thick steel sheet .

[seacoastartillery]

      LT25,   We have lathes and mills to process this thing, but here's why we would not touch it and you won't either if you think even a little about your liability.  First, it's too thin to be used "AS IS".  Second, it's an unknown as far as metallurgy is concerned, so appropriate types of machining and certainly welding cannot be known.  Third, you have no idea as to what amounts of stress that may have been applied to this item, and therefore, no idea what its remaining strength might be.  

     As far as it's use as a rifled gun tube, we doubt it very much.  For muzzleloading cannon, the 12 Pdr. Whitworth had one of the fastest twists at one turn in 55 in.  According to our calculations and also Dan's, your thing has about one in 9 or 10" which is far, far too fast for a 2" diameter projectile.  Finally, if the deal or the price seems to be too good, it probably is!  Good luck to you and think very carefully before you make one cut on that whatever-it-is.

Regards,

Mike and Tracy                            FYI, More info about rifling: http://www.graybeardoutdoors.com/smf/index.php?topic=108012.0

[RocklockI]

To the point : "N.F.W.!!!" , that's "bursting thin" in pretty much whatever normal material it is . That big wide mouth invites ....too much powder...way . "Live to do this nonsense when you are 75 years old" ...or more ..

I remember that as "wise information" from from a sponser on this board ! ...about 32 years ago .

FWIW I do know "something" of bursting ...cannons ,uh ,er things .    

There are simple "Professionally Made" cannons that are not much money , and will last a life time or four . 

rocklock

[Eyes Of Death]

Looks like an old down hole retrieval tool to small for oil field, more like water well stuff. The new tools have rubber liners that look the same.Should be made from 4140 or better. When you twist off a piece of drillstem it twists in the tubing not the threads, leaves a point behind. You just thread this on and pull out the pipe.