Tubing

[Runner]

In an earlier discussion we discussed tubing, but the question was whether or not it was seamless. Well, the answer seems to be NO!
After a couple of hour search, I found several tubes made of appropriate materials with the wall thickness needed. Then I went to McMaster Carr and checked. I found 513 1.00 x .250 x .500 tubing. I also found moly that would be acceptable. After finding the tube with the correct wall thickness to form the barrel in one piece, I then searched for seamless tubing. None of the appropriate material is seamless that I can find. The maximmum wall on seamless precision ground tubing with the proper specs for this application does not seem to exist. 3mm is max thickness in anywhere near rifle caliber tubes in seamless.
Am I saying that the tubing barrels are not safe? Nope, not at all. All I am answering is the original question. There does not appear to be a seamless tubing made that is appropriate for the application anywhere by anyone.
Again, to buy stock to form barrels in one piece made out of seamless high quality tubing will cost you almost as much as a decent barrel will. Apparently from all the reports the welded DOM steel tubing must work pretty well, but it is not seamless that would be best selected for an application where high pressure is applied and reduced quickly over and over again. I guess the next question is how well the DOM process blends and stabilizes the weld in the tubing.

 

[Grizzled Roberts]

A fellow in Indiana named Arlin Blair used to make smoothbore barrels out of high grade hydrolic tubing. Over the years he made a truck load of smoothbores from this tubing. I know that most of the smoothbores he built are still in use. I have never heard of a problem with Arlin's barrels.
I will confess I do not know the differance between hydrolic tubing and other pipes. He made me one 25 years ago, as barrel length is optional I had him make mine 50 inches long. ( some of the folks were using 50 inch plus barrels ) In the long run I found out I could not hold up this 50 inch barrel. I traded it off. A little elderly gentlemen named Dan Holiday wound up with this firelock. He has been kicking my arse with this
smoothbore for many years now! :thumbsup:

 

[bioprof]

Why would DOM barrels be any less safe than hand-made forge welded cast iron barrels that sell for over a thousand dollars?

 

[Darkgael]

Runner: Help me out here as I'm continually finding out how much that I don't know.
I was under the impression that DOM tubing was seamless. (I made a GB mortar out of a piece.) Is that not the case? Metals Depot lists DOM as seamless (http://www.metalsdepot.com/products/hrsteel2.phtml?page=rndtube&LimAcc=$LimAcc) - though I don't see sizes appropriate for the use that you have been discussing. Is that "seamless" note that they have just a trade thing and it's really welded or what?
Inquiring minds want to know...
Pete

 

[Runner]

No one said that they were not as strong as hand hammered cast barrels that cost thousands. Of course if we had period barrel failure rates today, the entire industry would be history by now.
DOM is not extruded seamless. It is welded and then formed thru several operations afterwards. Since the metal is stretched and formed after being welded, the weld is then a formed part of the piece. They list a .25 wall .50 ID tube of DOM. The thickest seamless is 3mm, or half that. I am not an engineer, so I can't comment past that.
In the first posting I stated that there was no seamless tubing available with the wall thickness needed to make barrels out of it. I got my head handed to me. Since I build airguns, I buy moly seamless for use with them. I was pretty sure there was no wall thickness available that would allow forming a barrel in one piece out of seamless. I assume that the builders do destructive testing with the materials they use, and that they know more about the materials they are using than I do.
It isn't seamless tho.

 

[flashpanner]

Why bother or even consider tubing for a M/L? I'd just stick with machined bar stock of a good quality alloy. What is to be gained by using tubing?

 

[Bountyhunter]

My thoughts also, Flashpanner. The time you spend screwing around with the DOM tubing would be better spent with a barrel blank of known quality, wouldnt it?

What I'm sayin is, that in the days of building guns and rifles, there were those who made barrels and sold em to those who made guns. :thumbsup: :thumbsup:

 

[Shifty]

Runner,have you checked with[url] www.onlinemetals.com[/url] for what you are looking for?

 

[mckutzy]

in the case of being cheaper, i would have to buy a barrel online, my gun stores in town dont have them at all, the nearet guy who sells them is probably a province or two away, or downsouth in USA. obvious safty is the main concern, but if im able to get a piece that im able to test and am confindent safe, than by all means this is a greater option. IMHO..

 

[Runner]

Yes, I looked on online metals and several others also. I buy my metal from Shapiros in town usually.
I never said what was available was not strong enough. I said it was not seamless. The 1.00 x .500 x .250 tube is pretty strong stuff. You just have to be careful of who you buy your steel from. Several businesses have been caught selling chinese steel with new markings and false claims. Several groups will tell you that DOM is seamless. It is not, and I can show you the weld seams in a bunch of it. The same tubing is sold by others only they don't lie about it being seamless. There is thickwall extruded seamless with walls thick enough for this purpose, but it is a custom order product as far as I know. It is also expensive. Several suppliers are selling chinese steel as seamless moly and sooner or later they are going to hurt someone.
Ask Dennis Quackenbush about buying steel.

 

[Darkgael]

Runner: Thanks.

Pete

 

[Darkgael]

Just now read through the Jan./Feb. issue of Backwoodsman magazine. There is an article about building a 6 ga. smoothbore. Interesting read, though not enough info and poor photos.
The connection to this thread is that he uses "schedule 80 seamless pipe. 1" bore diameter."
Makes me wonder....he hasn't been reading these threads. His load is 200grs. FFg and a 2.5oz lead/zinc ball.
He hasn't blown himself up yet.
Pete

 

[Runner]

If you want a 1 inch bore, then I can get you 1/2 to 3/8ths inch wall thickness on tube made of good materials I think. The problem is when you try to stay down under .75 ID.
There is a nice piece of moly laying in the driveway that I use as as a cheater because of this issue. It looked good until I started to hone it out to fit the valve that was going in it. I wanted a metal lip for the valve to sit against because of the pressure I was planning to put on the gun. A valve blowing out and sticking in your forehead is not a good thing! I was honing and wiped the piece out to inspect it. The weld seam is very plain after honing. Turns out it is a nice piece of chinese junk metal called Seamless DOM Moly tubing by the people selling it. There is a lot of it around. Course now, I am using .95 wall thickness on most of what I am doing, and that is plenty if I actually get seamless moly tubing. That would be my main concern in building barrels out of tubing. Getting proper materials cheap enough to make it worth the effort.
I can turn a 58 inch piece not counting what is in the chuck and steady. It would be very easy for me to contour a piece of tubing. No problem using the 5c fixture to cut the flats on the mill either. I may order some of the stuff with the .25 wall thickness and see what happens when I cut a piece off and hone it a little.
I bought a 1920's knockout gap bed Southbend a couple of years back. 16 x 24 x five feet usable travel. I don't have the power to do the cuts it is rated for, but it will cut if I take my time.
You have a nice day.

 

[Bubba45]

Sch 80 seamless pipe :shocked2: Sounds like the certified stuff we used for 300# steam when welding joints were required.After boring and threading for breach plug it wouldnt be very thick at bore and plug junction! The wall only starts around 3/16" thick. I think I'll stick with something a bit thicker.

 

[matt denison]

I read that article too. I was shocked that it got published. 200 grains of powder? He's nuts and I hope he isn't next to you or me at the shooting line when it blows. Maybe the worst part is the homemade lock works that don't explain about angles or hardening critical areas.

 

[Darkgael]

Yep. It's an article that's just tempting enough to be dangerous.
Pete

 

[Runner]

Is 513/4130 considered a good barrel steel?

 

[Bubba45]

Whats really scarry about it is having someone read it and think they can use common water pipe for the barrel and end up making essentially a pipe bomb :shocked2:

 

[fw707]

Well, I guess I'm the feller responsible for starting this whole mess when I asked the question about the "tubing" barrels, and I am sincerely sorry for any controversy that it has caused. But I would like to thank everyone that has replied for all of the good information that they have provided. I have decided to have my fowler built with a 44" Colerain barrel, and probably a 28 gauge, which seems to meet the general consensus of the smoothbore barrel gauge/caliber that shoots the best groups with a patched round ball. The gun will be used for some hunting, but mostly for our local club's "smoothbore" matches which require a tight-shooting RB load and a few shots at trap-thrown clay pigeons for the same match aggregate score.
Please accept my apology for the controversy that I might have caused, and I would like to thank everybody who replied for their opinions. :thumbsup: :hatsoff:

 

[TANSTAAFL]

I seem to recall they have been making extruded seamless steel boiler tubing and pipe for some time, some of it rather thick walled.