tubing for barrels

[razorbritches]

There seems to be some bias against tubing for barrel material I am new to building guns but my work experience has shown quality tubing to be an excellent material with great mechanical properties. what is the opinion of you men and why

 

[wmaser]

This topic has been beat to death already on this forum and no consensus has ever been reached.
Many will cringe when I say this but I, personally, don't have a problem with DOM tubing for gun barrels. I have used it and proof tested many pieces of DOM with no ill effects. I have never heard of a DOM failure. I don't use it on a regular basis but if I get ahold of a piece chances are I'd make something out of it for my own use.

 

[necchi]

This topic has been beat to death already on this forum

Oh Yeah !

and no consensus has ever been reached.

Truth to that!

I kinda side with the folks that will cringed with wild bill 2`s postulate.
I kind of figure that if it was a great idea there would be 1000's of guns on the market already using DOM tubing.
It's simple economics, Why would manufacures use expensive barrels if DOM tubing worked?

Are they out there? Yes.
Will I ever shoot or hunt with someone that has one? No.

 

[Zonie]

I've given my thoughts on this many times here on the forum.

Suffice it to say, if someone wants to use a rolled tube that was welded with an automatic butt welder and that has had the welds smeared to cover the irregularities and any incongruities of the weld joint it's their business.

I have yet to see any supplier of DOM tubing say in writing that it will withstand 20,000 psi of sudden internal pressure.
(Sound engineering says the safety factor with explosive pressure increases should be of a factor of 4).

 

[rich pierce]

Many of us would not fire original barrels, I guess, out of safety concerns over forge-welded seams. I've also got an original jaeger barrel I intend to use, and an original Spanish octagon to round 1740's barrel I intend to stock up. Proofing satisfies me.

I got a tubing barrel profiled by Ken Netting that I intend to use in a militia style musket for my own use. I'll proof it and then trust it. I got it instead of a drilled barrel because A) it was available immediately not 18-24 months down the road like most custom barrels; B) it had a better profile than anything available off the shelf and C) it is good enough for Ken. Cost was not the deciding factor. I'd pay an exta $100 for a drilled barrel if I was planning on selling the gun, just because I would not want to go through the hassle of discussing the pros and cons.

 

[razorbritches]

thank you men for your input and, the benefit of your experience. I did not know that the subject had been discussed on this forum and really chewed to bits on both sides. I have since run a few searches and , read the opinions pro and con. Especially useful where the ones on both sides that had facts. It seems that no one has actually run a battery of tests to destruction and , measured it against production barrels in a similar test. It could provide interesting information either way it went. Men again thank you for your experience and, rest assured the last thing I want is to learn the hard way

 

[schloss]

I would like to see someone do some real testing on the steels in question on this debate. I have never seen it. Part of the issue with tubing is the fear of it rupturing under the pressure rather than deforming.

I suppose I should go out and buy a piece and test it. I can do mag particle, dye pen, ultrasound, and x ray testing on it to get around the fear of weld inadequacy. But the material properties are what I would be the most concerned with. The internal pressure will be in the y-direction, but the greatest strength will be in the x-direction, which can also be an issue. it will be difficult to pull a tensile bar in the correct direction from the tubing, or to pull charpys, either.

Anyway, I would be interested in discussing this again. I choose no side on this discussion, but would be curious what the actual answer is. But if your barrel blows up in your face, I still say it's your own fault.

 

[schloss]

Also, what steels are going into production barrels currently, and what is going into Dom tubing?

 

[razorbritches]

that's me I am more interested in the actual results than to start an argument but, any test with results worth relying on would have to be a test to destruction. I would also prefer a test involving several pieces (not just one) to get an idea of expected average performance of the material .

 

[schloss]

Also, if anyone knows the yield and tensile strength on the materials we're discussing, that would be of note. Impact strength would be worth looking at, too.

 

[necchi]

any test with results worth relying on would have to be a test to destruction

Your right, and for all the years we've been talking about this,, Nobody has done it.

Every so often some hillbilly comes on and tells us he and bubba made a gun and it's been shooting just fine for years, but nobody has done a controlled test. Nobody.

 

[necchi]

Also, if anyone knows the yield and tensile strength on the materials we're discussing, that would be of note. Impact strength would be worth looking at, too.

That data is readily available online from the manufactures. And you could ask the people that makes the stuff if they would recomend the use of DOM as a barrel for an ML Rifle/Shotgun.

Why not go to the pro's instead of kicking the idea around with folks that build guns with real barrels?

 

[kaintuck]

I just buy lead pipe from the local hardware store......once filed and browned, nobody can tell~ :haha: :haha: :haha: :stir:


i wouldn't do all the work on the wood, brass, and carving if there wasn't a great barrel under it all! :idunno:

 

[Joe Sullivan]

Are you guys talk'n about making pipe boms? Cause we could have dummys holding the boms at arms length and get pictures.

 

[George]

Also, if anyone knows the yield and tensile strength on the materials we're discussing, that would be of note. Impact strength would be worth looking at, too.

Here are the specs on my DOM barrel:

Ultimate strength -104.800 psi
Yield strength -94,100 psi
Elongation in 2 inches -17.0%
Hardness (RB) -96.

Grade: 1026AK
C: .26
Mn: .69
P: .014
S: .005
Si: .020
Al: .040
Cr: .040
Mo: .010
Ni: .010
Cu: .020

Spence

 

[razorbritches]

I do not advocate the making of "pipe boms" but a test to destruction will yield invaluable data.

 

[davec2]

Razor,

I would note that truly seamless tubing is made routinely and it has no seam anywhere. No weld at all. It is made by piercing a hot billet and then drawing tubing of various sizes from the large, pierced billet. The "DOM" (drawn over mandrel) tubing is sold as such (i.e. "DOM Tubing") and is usually welded and then pulled over a mandrel to improve surface finish and mechanical properties. Both are made in tubing and pipe sizes and a wide range of wall thicknesses. In the aerospace world I use seamless tubing all the time for applications up to 150,000 psi. It is available. It is inspected to very high standards and, depending on the alloy, would be as good a material for a barrel as any.

By the way, the manufacturing process for seamless tubing is quite interesting from the piercing mill process to final drawing to size and wall thickness. Look it up.

Dave C

 

[matt denison]

The guys using tubing are the ones selling the less expensive stuff (fact)

If tubing is so darned great how come guys like Rice, Hoyt, Getz, Colerain, Green Mountain, Longhammock and North Star West doen't offer them?

Because they are trying to make the best that can be had, that's why. (fact)

 

[razorbritches]

Dave I am familiar with the process used to make true seamless and DOM tubing and you are right it is a pretty cool process. I am a boilermaker in the power generation industry and a certified welder so I am familiar with the hands on use of both products. I have no experience with aerospace quality tubing but it's specs are in a wide variety of very tough alloys.

 

[schloss]

12L14 free machining steel
Minimum Properties Ultimate Tensile Strength, psi 78,300
Yield Strength, psi 60,200
Elongation 10.0%
Rockwell Hardness B84
Chemistry Iron (Fe) 97.91 - 98.7%
Carbon (C) 0.15% max
Manganese (Mn) 0.85 - 1.15%
Phosphorus (P) 0.04 - 0.09%
Lead (Pb) 0.15 - 0.35%
Sulfur (S) 0.26 - 0.35%