tubing for barrels

[schloss]

The area of concern for me would be in the HAZ. There will be a line the length of the tube that is going to have different mechanical properties than the rest of the tube, due to the welding process. I can think of no reasonable way to test that area, because if you get a sample big enough to actually pull a reduced section tensile specimen out of, you're going to have different mechanical properties because of the mass of the piece.

I personally think that if - yes, if - a certain section of tubing is actually gun-worthy, it would be critical to inspect the full length of the weld with both RT and UT to determine whether that individual piece is sound or not.

Also, I saw on the Rice Barrels website that they were using 4140 for a run of barrels. I wasn't able to figure out what they're using in general, though. Anybody got this information?

I certainly will not argue that a much finer and straighter barrel could be made from bar stock, but I find this interesting, regardless how many times it has been discussed.

 

[razorbritches]

I saw on their website that 4140 was used for military barrels and some pistol barrels but nothing on the rest. 12L14 leaded steel has had problems as a barrel material in the past not sure I would trust it myself. Most barrel makers don't say what they use.

 

[Zonie]

davec2
I spent 40 years in designing aircraft gas turbine and jet engines and have never heard of an application that would use 150,000 psi of internal or external pressure.
We always used true seamless tubing but our pressure spike pressures seldom exceeded 3,000 psi.

We occasionally used tubing materials which had Ultimate Tensile strengths in the 184,000 + psi range but normally we selected materials like CRES 347 with a Ultimate Tensile strength of 154,000 psi.

razorbritches
As for 4140, we're talking about a material that can have a Ultimate strength of up to 284,000 psi with Yield strengths up to 251,000 psi depending on which heat treatment was used.

Materials like this are needed for modern smokeless powder barrels etc. but I'm sure Green Mountain, or anyone else would ever use such a material for a black powder muzzleloaders barrel.

As usual, I'll mention to the folks who might be confused by these high pressure numbers, they refer to the force needed to cause a piece of material that has a crossectional area of 1 inch to break.
The numbers do not represent the amount of internal pressure a pipe or tube made out of them can withstand before it ruptures.

 

[jerrywh]

I made one 11 ga. shotgun ot of it and it withstood some tremendous proof loads. I shot it fo a few years with no problems. BUT a good friend of mine made blunderbuss barrels out of it and the first two proofed out OK but the third one blew up with the first normal load he put in it.
Previous to that I made about three pistols out of it but since then I quit. I will never use it again. It isn't worth the risk to me. I like living.

 

[razorbritches]

Zonie thanks for the figures good numbers are great to have. You are right about tensile strength not equaling the pressure it takes to burst the tube especially in a shock load. Does anyone know what Green Mt. North Star West or any of the others do use?

 

[DickS]

As far as materials go, tubing could be made from the same sort of alloy as barstock.
The concern is with the method of manufacture. If there are seams, folds, flaws in the tube, it is obviously unacceptable. Someone who buys a piece of DOM from a warehouse has no real way of knowing if the piece is free from manufacturing defect. Proof testing is all very well, but all it does is demonstrate that the piece did not fail on that occasion; this is extrapolated to suggest that it won't fail in the future.
I suspect that there are a lot of tubing barrelled cheap shotguns out there.
The leaded screw machine steels cut beautifully. There are also concerns over whether they might have a problem with brittleness. A lack of ductility. If a barrel fails, it is better if it bulges or splits, rather than shatters. Lots of barrels have been made from these steels.

 

[schloss]

I'm going to emphasize my opinion again, in case everyone didn't catch it. I firmly believe that - in the event that you concede that dom would be acceptable for use as a barrel - you still need to inspect it on a case-by-case basis.

I personally don't trust proof testing as a way to validate a barrel. I personally think that proof testing will only test a small portion, and conditions may have been good enough on that occasion to get it to pass, but it won't guarantee every situation, case in point would be a barrel obstruction.

Anyway, keep it coming. If anyone is concerned, I am a NDT tech with the Air Force (Nat'l Guard currently), and an Ultrasound and Mag Particle tech in steel structures, and an AWS Certified Welding Inspector.

 

[davec2]

Zonie,

I worked for Rocketdyne for many years building rocket engines rather than gas turbine engines. Engines like the SSME (Space Shuttle Main Engine) run at a combustion chamber pressure of above 3,000 psi. The liquid oxygen turbopump discharge is close to 9,000 psi and the liquid hydrogen pump discharge is close to 10,000 psi. With engines that start up in milliseconds, water hammer pressures can easily exceed three or four times operating pressures.

Actually, the 150,000 psi stuff I have been involved with was mostly to do with the oil and gas industry.

 

[Birddog6]

Green Mountain uses 1137 for their ML Barrels. And you can tell the dif as soon as you start draw filing one or cutting a dovetail into one. Colerain uses 12L14. Rice has used several types of material, but the main material they were using was 12L14. Getz was using 12L14 on all of them I have bought from them.

That is unless some of them have recently changed materials. They used to post the material used somewhere on their web sites. I know Green Mtn. states it down at the swamped barrels, didn't check the others.

Keith Lisle

 

[razorbritches]

Men it seems that there are tubes out there that should easily handle the loads involved in both of your industries. A look at the types of steels used by reputable barrel makers and, the properties of those steels. Would be very educational to me. Why those properties are important to barrel performance whether it is a tube or a drilled barrel. Ultimately Men I want more than just an answer. I want the understanding to make intelligent selections on my own. So far your comments and the searches I have made inspired by them have helped my understanding greatly. Thank you all .

 

[razorbritches]

Thanks Keith this should point me towards some answers and, maybe a little understanding of my own.

 

[mikemeteor]

Lifted from a post on a different forum this summer, with a nod to Ezra.
/mm

>>>>>>
The following are all of the black powder barrel makers I am aware of, followed by the type of steel that they use for their barrels. This list is for informational purposes only. What can I say? This sort of thing interests me...

For those manufacturers that are listed but do not have a barrel steel cited is where I need assistance Obviously, if there is another barrel manufacturer(s), or if I have made an error, please sound off.

Longhammock - 12L14

Getz - 12L14

Bobby Hoyt -

Rice - 12L14

Ed Rayl - 8620

Green Mountain - 1137

Flintlock Construction, Inc. (Charlie Burton) - 12L14

Mark DeHaas -

Colerain - 12L14

Sleepy Hills Barrels - 4150

Jim Carpenter barrels -

Oregon barrel company -

 

i am a new kid on the block, and as such i got some questions

on this topic in particular

back in the day of ML's barrels were forged out of iron, in some shop, some with folded and some with twisted strips of iron of unknown quality. all of which were forge welded.

before that cast iron was used too?

so, the question of DOM seems reasonable to me.

here is my question

does anyone have a link or a picture of a DOM black powder barrel that met with catastrophic failure using black powder or one of the various replacements?

its hard for me to imagine a piece of DOM parting or splitting using black powder, thus illustrating it is of lessor quality than what our forefathers used for barrels back in the day.

i am not here to start a pissing match, i would just like to see a picture of a failure due to verifiable use of black powder of "any" load capacity.

call me curious

bob g

ps. this post looks like a response to one member, i goofed up there, this was directed to the group and no one individual.

nevermind, it appears this is how the forum software works! (remember i am a newbie)

 

[razorbritches]

Thanks for the numbers men they helped. In an earlier post on this subject I said I wasn't sure I would trust 12L14 because of some posts claiming it was too poor quality for barrels, but here we have several reputable makers using this very material. So I got out the fork I save for eatin crow,and went to diggin for the awnser. It seems to me that tensile strength was not the deciding factor, but the ductility or yield strength. The crow was stringy but I got him down right after I got my foot out of my mouth.

 

[schloss]

It is my understanding that many, many barrels failed "back in the day". But I wouldn't use that as justification for dom being good enough. I'm sure it's stronger than the old methods of barrel manufacture, but still not convinced that it is as safe as a drilled barrel.

 

[Zonie]

My data says 12L14 has the following strengths:
Hot rolled
Ultimate = 57 KSI (Thousand pounds per square inch)
Yield = 34 KSI
Elongation = 22%

Cold rolled
Ultimate = 78 KSI
Yield = 60 KSI
Elongation = 10%

1132 (I don't have data for 1137)
Hot rolled
Ultimate = 83 KSI
Yield = 45.5 KSI
Elongation = 16 %

Cold Rolled
Ultimate = 92 KSI
Yield = 77 KSI
Elongation = 12 %

While these numbers are interesting, getting back to DOM tubing, it comes in several different materials. Among these are 1010, 1018, 1020, 1026, 4130.

While 1026 has some pretty good properties and some of the smoothbore makers that use DOM tubing supposedly are using it, without getting the material certifications that come with all steels from the major companies, the buyer is taking the sellers word for the type of material his tube is made from. That could mean the actual material properties are considerably weaker than the desired material.

Other things to keep in mind are back in the days of the Civil War the Military reached the conclusion that the minimum barrel wall in the area of the breech should be at least .200.

Proof testing can create weaknesses that didn't exist before the test, so a barrel that passes a proof test isn't necessary safe. Materials with low elongation are more likely to develop internal weaknesses from being overstressed.

Any proof test that is conducted must have at least one non-destructive test done to determine if a flaw exists.
With a steel tube the best test is a magnetic particle test such as a Magnaflux which can find both surface and internal flaws.

A poorer less expensive test would be a Florescent Penetrant test which can only find surface flaws.

Cost prohibitive tests like X-Ray and Ultrasonic tests can be done if they are available.

The bottom line is, without these post test examinations one can easily create a potential bomb by proof testing.

As for the barrels of old that were mentioned, the weld joint for the forge weld were almost always lap joints, not butt joints.
The material was wrought iron which has some pretty good elongation properties.
Lap joint forge weld barrel failure was fairly common even after the barrels were proof tested.
There are numerous news reports and letters written "back in the day" existing that tell of persons maimed or killed by the barrels on their guns exploding when their gun was fired.

Although I don't have pictures of failed DOM barrels I can say that when we are speaking of a life/death (or life/maimed) situation a picture of one failed barrel isn't needed.

With the various quality barrels available today, using a cheap material to save a few bucks could end in a disaster.

 

i think you all have made excellent points, one of safety is paramount to all of us, or at least it should be.

not to belabor a point but to further discuss a bit, if i may

the dom tubing i used to get from my supplier in tacoma "always" had all its specs printed down the side of the outer wall, right down to lot number.

also there is no way on earth i would be convinced an forge weld is better than a mechanized weld done in a 1st world country. most especially given that the tubing is then drawn over a mandrel and through dies for sizing which further improves the steel in the weld zone.

i took a bit of time to look into the pressures common of bp and find that appropriate loads of appropriate granule size produce upwards of 25kpsi, which i have to admit is much higher than i would have expected.

so i would have to side on the majority position that would err on the side of caution and not use tubing of unknown quality.

a couple more questions if i may

one would intuitively think (and i realize this is often folly) that a barrel that was not up to the task and did not catastrophically fail would however show some signs of expansion in the breach area, couldn't that expansion be measured with a micrometer? if i had a barrel that started life at 1.000 and suddenly after firing many rounds or after a hot load then measured 1.001 or more, would tend to tell me that the barrel is not up to the task? do you guys check your barrels from time to time in this manner to see how they are fairing?

also there is the question of rifling types, some/many grooves are made with sharp shoulder at the groove to land interface, this would ordinarily put stress risers at these area's of the barrel, and in the case of a failure i would expect the crack to originate from one of these sharp corners?

more questions looking for answers, if you guys have links to help me with these please let me know.

thanks
bob g

 

[jerrywh]

The barrels I bought from long hammock were made from 1137 and Oregon barrel co. uses 12L14. I have known Joe Williams for over 20 years. He just made me a barrel about 30 days ago. By the way Oregon barrel co. barrels are super nice and it's a short wait to get one.

 

[matt denison]

Lifted from a post on a different forum this summer, with a nod to Ezra.
/mm

>>>>>>
The following are all of the black powder barrel makers I am aware of, followed by the type of steel that they use for their barrels. This list is for informational purposes only. What can I say? This sort of thing interests me...

For those manufacturers that are listed but do not have a barrel steel cited is where I need assistance Obviously, if there is another barrel manufacturer(s), or if I have made an error, please sound off.

Longhammock - 12L14

Getz - 12L14

Bobby Hoyt -

Rice - 12L14

Ed Rayl - 8620

Green Mountain - 1137

Flintlock Construction, Inc. (Charlie Burton) - 12L14

Mark DeHaas -

Colerain - 12L14

Sleepy Hills Barrels - 4150

Jim Carpenter barrels -

Oregon barrel company -

 

[bob308]

hoyt uses 12L14