pipe barrel build?

[paulvallandigham]

Jeremy: If you " work in an office", you have to know an engineer, or someone who does. Call them, and ask them about anything like this.

I have a twin brother who is a Professional Mechanical Engineer, with a master's Degree in Control theory. He has a couple of reference books at his desk he turns to and looks up the various strengths of metals used in all kinds of things. He says these are standard tests for Engineers, both Civil, and Mechanical.

I happen to agree with those who have already expressed the sentiment that this article should never have been published. When I was 7 and 8 years old, we kids experimented with making pipe bombs- small ones-- which we blew up in deep holes we dug out in the back of the garden. Mostly, it was curiousity to see if we could do it. We used gunpowder from blank cartridges that failed to fire at the Memorial, and 4th of July parades, flash powder scraped from unexploded firecrackers, smokeless powder someone found in their father's reloading room, etc. We knew that what we were making was seriously dangerous, even at that age, and that is why we spent half an hour digging a deep hole in the ground to contain any explosive " Shrapnel. ( think of a post hole.) That is also one of the reasons I don't by excuses that young kids over age 5 don't know a real gun from a fake, and can't appreciate their danger. Unless the kid is retarded, I don't buy it. I have had too many very young students in my Hunter Safety Classes who have been well motivated and trained by their parents before taking the class, to believe that all kids are that stupid.

Obviously, the author of this piece is a victim of retarded development. He's stuck on "5".

 

[wbyman]

How many of the posters here that know a tubing barrel will blow up have ever built a barrel made from tubing and shot it ? How many of those have had that barrel blow up ? Probably none. It is great to give your opinions but in this case it is probably not based on fact.

 

[Mike Brooks]

How many of the posters here that know a tubing barrel will blow up have ever built a barrel made from tubing and shot it ? How many of those have had that barrel blow up ? Probably none. It is great to give your opinions but in this case it is probably not based on fact.

Big difference between thick walled tubing and gas pipe. At some point common sense should kick in.....

 

[flashpanner]

let me know when you touch it off, I will be far far away(like many states away!) Sounds like a suicide project. Stick with known metalurgy and barrels made by reputatable manufactures. Don't scrimp or take short cuts here! Your life and safety of those around you is at stake.

 

[oldarmy]

If he wants to blow himself up. I don't really care.
Isn't there an award for stupid stunts.. something about DAWIN??
But kidding aside, we don't need the bad press that will go along with this stupididy.
A couple of Yahoos just blew themselfs up this summer in Vermont with a homemade cannon.
As an aside
Mr. Brooks, I saw that fowler you build for my friend Shimmelsmith.
You should post it.

 

[Cutfingers]

I don't believe in referring to people as stupid, especially when they simply asked a question for advice to begin with. Anyway, pipe and black powder ARE the main ingredients for PIPE bombs and it would not be advisable to proceed further.

 

[Bountyhunter]

The posters here are not referring to Jeremy as the stupid one if you reread the thread. They are referring to the author of that article as the one "Stuck on Stupid".

 

[Cutfingers]

Good, I stand corrected.

 

[oldarmy]

Questions are never "stupid".
I never ment to imply Jeremy was either.
Was trying to say.
Guns have a bad enought reputation now. We don't need "stupid" people doing "stupid" stuff with black powder and pieces of pipe.
If you put a stock on it,,,it becomes a gun.
I just saw a tutorail on building a "zip gun" out of a piece of plastic tubing, matchheads, and epoxy.

 

[jerem0621]

This is the reason I posted this question is because I want to build a muzzleloader. I read the article and just wanted some answers and consensus, both of which I have obtained. Am I ignorant of barrel strength? Well, Yes I am. All I know about barrel strength is what my Thompson owners manual tells me. I know what I originally posted must sound crazy, I'm very cautious with my firearms and yes I am very concerned about my life and limb. :grin: Thanks everyone for the stern warnings

I'll forget about the pipe gun and just save a few extra bucks and buy a good barrel to build my matchlock or flintlock. :thumbsup:

Jeremiah

 

[mckutzy]

well u have come to the right place.... :hatsoff: :hatsoff:

 

[Zonie]

jerem0621: Please read the post about DOM tubing in this link:
DOM TUBING FOR BARRELS

Pay special attention to my comments on page 2 of that post.

To save me some writing about PIPE, I have copied a part of that link that I wrote and I will post it here:

Getting to the real reason for this post, I sometimes hear folks talking about using common pipe to build a barrel from. They sometimes say, "I found some Schedule 80 or Schedule 160 pipe with really thick walls and I'm going to build a barrel with it."
I think I should talk about this a bit.

First off, regular pipe is always made by rolling a flat plate into a tube and welding the ends. This may be a butt weld or a lap weld and pipe made in this manner has the same built in weakness as welded tubing.

Regular pipe used to be made from iron but now is usually made from the cheapest steel that can be found. That is because, generally speaking, pipe is intended for relatively low pressures.

Looking thru a "TUBESALES" catalog there are several different Schedules of pipe available.
The typical Schedule 40 that's used in household water and gas applicatons, Schedule 80 that is used for moderate pressures, Schedule 160 that is used in fairly high pressure systems and a Schedule XX STRONG for special applications.
It should be noted that in all of these applications a rapid application of pressure is never considered.

Using this catalog I decided to run a few numbers for a shotgun barrel made from the Schedule XX Strong.
They show a "1 inch" pipe of this Schedule which has a .358 wall. The outside diameter is 1.315 and the bore is .599 (a little smaller than a 20 guage).

A well known source specifies a tensile burst strength for all plain pipe as being 40,000 PSI for a butt welded pipe.

Using Barlow's Formula for calculating safe vessel (container) pressures which is "P = (2T X S)/D" where T is the wall thickness, S is the tensile strength of the material and D is the outside diameter of the vessel.

For this XX STRONG pipe, the numbers look like this:
P = [2 X .358 X 40,000]/ 1.315 = 21,779.47 PSI This pipe is not safe at this pressure.

It must be noted that this is the ultimate pressure at the time of failure and the working pressure is specified as being only 1/10 of that value. In this case, the working pressure would be 2,178 PSI.

Knowing that almost no one will be able to find some Schedule XX STRONG pipe, I then ran the numbers for some Schedule 160 pipe.
I found some "3/4 inch" Schedule 160 pipe that has an outside diameter of 1.050, a wall thickness of .218 and an inside diameter of .614 (about a 20 guage).
Plugging in the numbers gives:
P = [2 X .218) X 40,000] / 1.050 = 16,609.5 PSI This pipe is not safe at this pressure.
1/10 of that value to obtain a safe working pressure is 1,661 PSI.

These "working pressures" by the way are the maximum pressures I would say are safe.

Unfortunately I do not have any data for a 20 guage shotgun however I do have data for a 12 guage (Lyman Black Powder Handbook).

For a 26 inch modified choke barrel Lyman shows the following pressures:
2 3/4 dram (75 grain) & 1 1/8 oz # 7 1/2 shot =2,700 PSI with GOEX 2Fg powder.

3 dram (80 grain) & 1 1/2 oz #4 shot = 3,600 PSI with GOEX 2Fg powder.

I might also point out that usually the smaller bore guns have greater pressures than the larger bore guns.

It should be noted that both of these 12 guage pressure values exceed the safe working pressure of even the Schedule XX STRONG pipe so it is obvious that the Schedule 160, 80 and 40 pipe are to be considered dangerous for use as a barrel making material.

Although it is easy to say, "Well old zonie is just covering his butt with that ridiculous 1/10 value. I can use 50 percent and be plenty safe."
remember, by exceeding the calculated working pressures you are subjecting yourselves and those around you with DEATH or worse. Worse includes being blinded, paralyzed or loosing major parts of your face. This is not an area that people who don't understand Engineering principles should mess around with.


The above isn't all that I wrote and I urge anyone thinking about DOM tubing or Pipe to use the above link and read ALL of what I wrote. It may save your life.

 

[talon]

Articles like that are why I canceled my subscription to Backwoodsman 15 years ago.

 

[FPDoc]

I wonder if you can get some kind of "safety discount" from your insurance company (like with replacing a windshield) if you promise to only build your firearms with high quality barrel materials? :grin:

 

[jerem0621]

I think I'll just leave backwoodsman on the shelf next time I see it for sale. lol.

Zonie, thank you for the information? Clearly a pipe is not just a pipe. Thanks everyone for probably saving my life :hatsoff: before I went and did something stupid.

I love this forum!

Jerem

 

[DonH]

jerem0621:

First off, regular pipe is always made by rolling a flat plate into a tube and welding the ends. This may be a butt weld or a lap weld and pipe made in this manner has the same built in weakness as welded tubing.

I am not posting to dispute what has been said about the wisdom of using pipe for a barrel. What caught my attention is the above statement and how it compares to an article I just read about making barrels for rifled musket barrels for the US military up to the 1860s.
A picture was shown with the article of a machine used at Harpers Ferry Arsenal which formed barrel "tubes" just about as described above. The joint was then hammered welded. The seam was said to have been just about invisible on barrels made on this latest type machine. Regardless, this barrel was a welded seam tube and made from metal very little, if any better than wrought iron. Prior to that time barrels were hammer welded around a mandrel and one should wonder about the "bursting strength" of those old thin fowler barrels.

 

[Many Klatch]

Back when smooth bores were being newly rediscovered in the 80's. I knew of a couple of guns that were made from high pressure steam pipe. Some of them are still shooting and shoot well. The guy that made them had a connection with a power plant. I assume that high pressure steam pipe from the 1980's is probably better stuff than seamless schedule 80 pipe from China today.

Just my opinion. I thought that the guns were interesting, glad they worked, but I bought my barrels from Don Getz.

Many Klatch

 

[Zonie]

"The guy that made them had a connection with a power plant. I assume that high pressure steam pipe from the 1980's is probably better stuff than seamless schedule 80 pipe from China today."
-----------------
Having never worked at a Power plant, I'm only guessing but I would expect the "pipes" that carry high pressure steam in an American Power plant would be made using true "Seamless Tubing". It also would most likely be made from a high quality steel high strength steel rather than the low quality low carbon steel that is commonly used for making common 40, 80, 160 or XX Strong series pipe.

As for gunmaking methods used in the early to mid 1800s, yes both longitudinal seams and spiral seam welded iron and steel were used to make black powder barrels. These were always proof tested using very large powder/ball charges and, even with all of this testing, there are a great many documented cases of peoples guns exploding and killing or maiming them.

With the great availability of gun barrels from reputable makers at reasonable prices available, in my opinion trying to use DOM "seamless" tubing (which isn't) or common pipe is just plain foolish.

 

[aldebaran]

You can do it .... with some knowledge.
First of all: seamless means that the tube hasn't been welded. For pipes look at[url] onlinemetals.com[/url] ...
Second: not all the alloys are the same. You need the right alloy for the right job! I'll suggest you looking in gunsmithing forums (like homegunsmith). Ask there ... not many are BP experts, but they know what they say!

 

[DBox]

I bought the magazine and checked out the article. For my part I'll just say that I'll stay with what I've got.