DOM or Pipe Barrels

[JEH]

I acquired a nice Ken Netting Type G trade gun a few months back. The 45" barrel has a weld seam full length on the inside. I assume he machined the profile from a piece of DOM tubing. Anyone have any experience with these? Are they safe to shoot with the relatively low BP pressures.

[Bob Roller]

I acquired a nice Ken Netting Type G trade gun a few months back. The 45" barrel has a weld seam full length on the inside. I assume he machined the profile from a piece of DOM tubing. Anyone have any experience with these? Are they safe to shoot with the relatively low BP pressures.

We all know what pipe is but what is DOM??
Bob Roller

[JPK]

D.O.M. Means drawn over mandrill. My cannon is 1126 dom and stands up to 500 grains of cannon powder and a 1.06 pound lead ball. I proof tested with 800 grains of 1fg and a two pound slug.
This tube has no discernible weld.

[rich pierce]

I acquired a nice Ken Netting Type G trade gun a few months back. The 45" barrel has a weld seam full length on the inside. I assume he machined the profile from a piece of DOM tubing. Anyone have any experience with these? Are they safe to shoot with the relatively low BP pressures.

Ken used a lot of these. So far, so good. I’ve got one in the corner of the shop; haven’t used it yet. Very nicely profiled.

[JEH]

Thanks for the replies. When I was a kid I used to make cannons out of 3/4" gas pipe. I guess surviving that made the age and wisdom kick in.

[Clowdis]

DOM tubing would not have a seam because it is drawn over a mandrel instead of rolled and welded. The mandrel would erase any joint line. What you may have is ERW (electric resistance welded) tubing which is a whole 'nuther thing. I would not trust the welded tubing. Most racing organizations will not even allow a racer to make a roll cage from ERW tubing, it has to be DOM. Could the groove running the length of your barrel be a scratch instead of a seam?

[Daryl]

I am assuming the DOM is what is called, Seamless Tubing?

[JEH]

It's definitely a seam. Not as pronounced as a ERW pipe seam but it's there. Been a TIG welder fabricator for alot of years so I have seen miles of pipe. As prolific a builder as Ken is I wouldn't think he would peddle pipe bombs. Just looking for other opinions. 

[bob in the woods]

Ask Ken .

[RonT]

Any chance of taking a pic?  Can you feel the seam with a pin or sharpened wire?  Since you only mentioned the I.D., assume there is not indication on O.D..
Again, ask Ken.
Cheers,
R

[JEH]

Anyone have Ken's contact info? I can't seem to find it.

Thanks

[Hungry Horse]

 We are talking about a modern replica of an original that was FORGE WELDED out of wrought iron. Think about it.

  Hungry Horse

[JEH]

Point acknowledged!
Thanks guys

[Eric Kettenburg]

I have known a number of people making barrels out of DOM hydraulic tubing, including a good friend who used to work for a division of Sandvik and was able to go over the entire process with me.  There is no weld in DOM tubing.  Whether or not it is suitable for barrels is an entirely different can of worms and I know for sure there are some here with extensive metallurgic knowledge who certainly have informed opinions on the matter.  I have not known anyone making barrels out of welded or seamed tubing.  I don't really know what to think about that.  Yes old barrels were welded.  This is 2022, not 1722 or 1822.  I suspect there are one heck of a lot more attorneys around now than there were 200+ years ago.  Just saying.

[bob in the woods]

You could always ask someone like to Charles Burton to duplicate the barrel for you.
Problem solved .

[Mike from OK]

I have known a number of people making barrels out of DOM hydraulic tubing, including a good friend who used to work for a division of Sandvik and was able to go over the entire process with me.  There is no weld in DOM tubing.  Whether or not it is suitable for barrels is an entirely different can of worms and I know for sure there are some here with extensive metallurgic knowledge who certainly have informed opinions on the matter.  I have not known anyone making barrels out of welded or seamed tubing.  I don't really know what to think about that.  Yes old barrels were welded.  This is 2022, not 1722 or 1822.  I suspect there are one heck of a lot more attorneys around now than there were 200+ years ago.  Just saying.

I've read a few accounts of loading practices from back then. Some are absolutely hair-raising. I wouldn't dream of pulling some of those stunts with barrels of modern material... nevermind a hand forged barrel.

Mike

[yulzari]

Comparing old forge welded barrels with modern electric welded tubing you are not comparing like with like. Old forge welded barrels were wrought iron with a different failure mode, being softer and liable to bulge and split rather than burst open spraying shrapnel around your hand/head/neighbour. Even so the better ones were forged into a spiral seam and twist/Damascus incorporates steel in with the wrought iron.

As to the strength of DOM compared to bored out solid steel, whatever is used simply has to be able to bear the load. Even cast iron did the job with powerful artillery pieces by just using obscene amounts of cast iron.

The material type is irrelevant as long as you use enough to do the job. There are more subtle effects from stiffness and mass that make good type of modern steel a better choice but we have seen steel lined aluminium for one work.

This is one advantage of a formal proof process. It does not care what the barrel is made from. Only if it is safe for the task asked of it. Personally I have no problem with a good piece of DOM hydraulic tubing of sufficient strength and passing a proper proofing.

[RonT]

If I were to make a DOM tube I would first slit slit a width commensurate with the diameter of the tube I want to start with, prior to subsequent operations, from a cold rolled or hot rolled coil.  I would add a tad to the width 'cause I'm going to squish it together when I weld it, I'll scarf off the excess after welding.   Then I will run it through a shot blaster to remove scale (Hot rolled), or just because, if cold rolled.

Then it goes into a buncha' forming rolls which bend it across the flat kinda' 'W' shaped, then to round.  Now I'm going to heat the edges really hot and push them together to forge weld them.  Now I have a tube with a ridge line of squished out steel on both the inside (I.D.) and outside (O.D.).  I'll remove that with a cutting tool conformed to the I.D. and the O.D., and remove the burr.  An NDT will show me if I got a good weld.  If not, I'll scrap the guilty length, and cut the remainder to lengths suitable for mass production.  Think 30 or 40 foot lengths.

Next I'll run it through a Normalizing furnace (1700*) which will anneal the weld line.  Then off to an acid bath, and application of drawing lube (Animal fat based, really. sound familiar?)

For those who haven't fallen asleep, or got bored and left the room, now the fun starts. DOM!
 
A point is pressed on the leading end of the tube so it can be pressed into a die (O.D.), by a mandrel (I.D.) on a captured rod.

A carriage containing a set of inertia pliers (the more the pull, the more the grip) grabs the point and reduces the tubes dimensions on the O.D. by the die, and I.D. by the mandrel.  Excess goes into elongation.  In some cases this process is repeated several times.

If, big If, the NDT missed a lip on the scarf, it just became part of the tube, and an issue,  Or, maybe a score by 'pickup' on  the mandrel which may have been what the OP saw.

There's the 'Cliff Notes'.

Cheers,
R

   

 

[Eric Kettenburg]

That's interesting and no I did not fall asleep!

My friend who used to manage at a sandvik plant did it differently.  They started with just a huge hunk of steel, usually stainless in his division, and basically heated it up to whatever temp necessary to punch a mandril through it.  Then it went through various hot extrusion processes and drawing processes to end up with a (obviously) much longer piece of extruded tubing with the desired id and od dimensions, the finished product having never been through any weld process whatsoever.  It was entirely hot punched/drawn/finalized or whatever the technical terms are.  I don't know what kind of annealing process it may have gone through although I know they were pickled afterward in an acid bath.  I don't think I'd have much of a problem trying some proof loads out in a barrel made like this, knowing there was no weld seam at all involved.

He and I ran a bunch of stock blanks and barrels down to Fred Miller one time @ 23-24 years ago and he brought along a 46" barrel he made up at work for a bess made out of this stainless tubing.  Allen was there at Fred's shop and took a look at it, said 'Great get a piece of plastic and you can have a synthetic bess.'  Smarta$$.

[RonT]

Our mill is the birthplace of seamless tube in the U.S.*,  Mannesmann process.   I didn't go into seamless, wasn't in the OP's question.  In 25 years I supervised either directly or indirectly every operation there, have a fair idea of 'how it's made'.  I would sooner make a barrel out of welded vs. seamless (our mill) due to inherent I.D. configuration, picture a spring pulled to elongation.  Incidentally, the wall at the weld line on a welded tube is thicker, no matter how many times it's cold drawn.
When I was over afternoon and midnight shifts I saw some strange tubes come out of the bench room, wink and a nod.
Btw, I have a Ken Netting barrel on my Graig Osborn built New England Fowler, and have no problem with that.   
Cheers,
R

[Eric Kettenburg]

RonT that is also very interesting.  So when you say that you'd prefer a welded tube as opposed to seamless, why is it that you say that?

I'm genuinely interested.  I've not been involved in any plant making either kind of tubing, obviously, and frankly I've always just stuck with barrels from companies like Rice or GM or Rayl or (years ago) Getz etc. who were drilling out solid stock.  I've seen a number of different guys over the years make barrels from various types of tubing, but have always been a bit leary only because I just don't know enough about it and the processes involved.  As I mentioned, I only know what my friend's plant was doing based upon what he was telling me.  I couldn't say if it was suitable or not for gun barrels.  I would think at the least that any of the different types of tubing under discussion here would need to be reamed for consistent ID, so that's never really been something I would potentially be concerned with.  Mostly, I would be concerned with structural integrity and also potential failure - and more importantly, the manner in which a failure might pop.  Shattered pieces, like a grenade, or a split like forged barrels of iron were wont to do?

[RonT]

Primarily due to the bore being straight vs spiral due to oscillation of the piercing point which floats on the piercer bar.  Is insignificant but there. Runout comes to mind.  Sure, it would work, but also play mind games with my shooting.
 Again, have seen a few gun barrels and choke tubes made ‘under the wire’.  The welded tubes available were/are 1020/1026.
Cheers,
R

[Hungry Horse]

 Prior Mountain Bill Newton used gas pipe for the barrels on his tradeguns. I never heard of a failure.

Hungry Horse

[Dphariss]

I have known a number of people making barrels out of DOM hydraulic tubing, including a good friend who used to work for a division of Sandvik and was able to go over the entire process with me.  There is no weld in DOM tubing.  Whether or not it is suitable for barrels is an entirely different can of worms and I know for sure there are some here with extensive metallurgic knowledge who certainly have informed opinions on the matter.  I have not known anyone making barrels out of welded or seamed tubing.  I don't really know what to think about that.  Yes old barrels were welded.  This is 2022, not 1722 or 1822.  I suspect there are one heck of a lot more attorneys around now than there were 200+ years ago.  Just saying.

All the Springfield rifle musket of the civil war were skelp welded “best iron”. Then rolled to shape and length then heavily proved with a 2” spaced Minie ball.
But this was done by people who knew how.
I suspect, in fact I am pretty sure, that in a thin wall barrel good iron was a better barrel than the steel then being made.
DOM might be OK but it would depend on several factors. However, hydraulic tubing is subject to shock loads like a gun barrel so tubing made for this probably is not a work hardening alloy.
We,
Welded tubing? For a gun barrel? Not putting it next to my face with 10-20k psi.

[Daryl]

The vent-less muskets made in India and sold here and in the States, are made from "high tensile strength tubing".
As they do not have vents, they have not been "proved" however will show all the "copied" proof marks as if made in England or France.