DOM steel tubing as smoothbore pistol barrel

[Gustavo Hoefs]

When I was thirteen I made my first muzzle loader out of a short section of galvanized pipe, yes I lived and no it never blew up. That being said I was looking at piece of drawn over mandrel steel tubing I am using for a project ( not a barrel ) and I started thinking this stuff looks pretty tough. Last night I ran across an online resource called yarchive dot com / metal. There were copies of emails by a guy named Robert Bastow who claimed that gunsmiths of old would have been beside themselves to have DOM tubing to use for barrels. My question to the forum would be why wouldn't this work for short barrels on pistols up to say 15 inches ? A .45 caliber barrel can have wall thicknesses of as little as 0.181"

 

[coloradoclyde]

 

[Gustavo Hoefs]

I do appreciate honesty.

 

[Grizzly Adams]

I think I remember hearing/reading that some India made guns used the stuff for barrels. Good chance you will be fine, but always the risk that you won't. If your going to make a barrel, I would use nothing less than seamless hydraulic tubing. Make a couple, and test/proof them *remotely*. If they exhibit any kind of stress, avoid it.

 

[necchi]

op:

 

[coloradoclyde]

Yep! this is going to be a good one.... op: op:

 

[Shifty]

Make no mistake I am not recomending DOM for making a ML Barrel but you can buy different grades of it starting at SAE 1008 -TuffDOM 620,do some on line searchs,maybe Zonie or some of the other Engineers on here will give some replys.

 

[Gustavo Hoefs]

I will check that out. The heavy wall that is available is 4140. I did some further looking and find that it is heat treatable and used for modern barrels. I think proofing is the key here since the original barrels were welded seams and the wrought iron probably not as good of quality as even today`s low end mild steel. Do you know if there is a chart available on load, caliber & pressure specs?

 

[Gustavo Hoefs]

Thank you! no advise given and none taken

 

[coloradoclyde]

Here are some old discussions on the subject...

http://www.muzzleloadingforum.com/...p?tid/251884/fromsearch/1/hl/Dom|tubing/tp/1/

http://www.muzzleloadingforum.com/...p?tid/275759/fromsearch/1/hl/Dom\|tubing/tp/1/

 

[George]

Here's one with some actual evidence instead of speculation. Read the whole thread, it will be worth your time.
http://www.muzzleloadingforum.com/fusionbb/showtopic.php?tid/260557/fromsearch/1/tp/1/

Spence

 

[coloradoclyde]

Thanks Spence,
There are so many old discussions about DOM it's hard to find the good ones..... :hatsoff:

 

[Gustavo Hoefs]

Hi C.C. Thanks to you and Spence for the links. I want everyone to know before I asked the question I did do a search but none of these DOM discussions popped up, not sure why ? I can understand why someone would be for using this material and I can understand why someone would be against using the material. From Zonies explanation of it the stuff looks the same regardless of the content. Maybe a bad piece gets mixed in with the good pieces. Maybe there was a hiccup in the machine manufacturing performance that day. Reducing risk seems to be the point and convenience or saving money does not reduce risk.

 

[Gustavo Hoefs]

I ve seen discussion about measuring a barrel before and after proofing. Has anyone ever suggested magnaflux process for checking a barrel after proofing ? You know like engine builders use ?

 

[coloradoclyde]

Re-read what Spence posted.....Magnaflux discussion is in there....

 

[eggwelder]

very good read

 

[DickS]

For further discussion...
What about 4130 aircraft grade tubing?

 

[frogwalking]

I bought this barrel from DGW. They did not tell me it was DOM. That was a minor issue compared to the breechplug installation. In any case, it has been fired several hundred times with ball as well as buckshot. 5/8 inch is 20 gauge. I am not approving of DOM for barrels, just telling you my experience.

 

[Zonie]

For further discussion...
What about 4130 aircraft grade tubing?

AISI 4130 is often called "chrome moly" because of the presence of chrome and molybdenum in its makeup.

While there is no doubt it is a stronger material than AISI 1018 or 1020 there are several things to keep in mind.

4130 tubing is a welded tube like DOM tubing. It is annealed and cold drawn to size it.

To allow for the sizing/drawing operation(s) the tubing is annealed to a dead soft condition.

During the sizing/drawing process the material will "work harden" to become harder and stronger but the final strength is far below the strengths the material is capable of.

This is the condition the tubing will be shipped to the customer.

Examples of what I'm saying is, fully heat treated AISI4130 can have a tensile strength of 102,000 psi with a yield strength of 78,300 psi.
Elongation at this strength can be up to 24%.

Comparing this with a simple low carbon steel like 1020 with its tensile strength of 55,000 psi (HR) and yield strength of 30,000 psi (HR) and elongation of 25% seems to show a major improvement in strength.

The fly in the ointment is the tubing is not heat treated when you receive it.
It is shipped in the work hardened condition from the last drawing.
It's properties will be around 90,000 psi tensile, 80,000 psi yield and the elongation will be around 10%.

There is also the issue of documentation.
Steel looks like steel and without the full material documentation for the piece of tubing it is anyones guess what the tube is actually made from.

Although I'm hesitent to suggest that DOM or CD tubing could be used for a gun barrel I will admit that using 4130 for a pistol barrel should be safe.

That's said knowing that pistols fire smaller powder charges than rifles so the low pressures from a typical pistol load should be all right.

Anyone trying to use this material for a gun barrel needs to remember, generally speaking, I do not recommend DOM's use for a blackpowder gun barrel.

 

[DickS]

As far as documentation goes, aircraftspruce.com offers this, for purposes of use of the material in aircraft. I would think that material intended for use in aircraft would be made to the highest standards - the likelihood of flaws and drawing inclusions should be extremely low.
Are not the majority of center fire rifle barrels supplied in a stress relieved condition, particularly cut and button rifled barrels, the exception being hammer forged barrels, which may be work hardened, unless stress relieved following hammer forging?