Questions on building Blunderbuss


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yakkingallover
August 25, 2008, 10:27 PM
Hello all, this is my first post in black powder mainly because I have just decided to begin building a blunderbuss. I have a question concerning the barrel material. I have procured a section of 1inch i.d., .250 wall thickness DOM tubing I plan to use for the barrel. I am a machinist buy trade and feel that this material will be more than suitable for the purpose but I am seeking the wisdom of someone who may be more familiar with a project like this. Any advice or criticism is welcome. I thank you all in advance. Bryan...

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Loyalist Dave
August 25, 2008, 10:51 PM
How do you plan to flare the muzzle? I ask as there are companies that sell pre-flared barrels, and you don't have to worry about weakening the walls or splitting the tube.

What sort of lock will you use? The proper blunderbuss was a type of coach gun, and you should have a secondary safety, like a dog-lock or a sliding bar lock (imho) to be correct.

LD

yakkingallover
August 25, 2008, 11:21 PM
still working on that, I have a few ideas including maching a seerate flare and tig welding it to the end of the barrel then smooth everything back out. For this first attempt I may go for functionality over pure historical accuracy.

4v50 Gary
August 26, 2008, 01:17 AM
Don't make a barrel when you can buy one. Vernon Davis sells them stonewallcreek@earthlink.net or 434-993-3357. There are others, but that's the first outfit that I found in an old copy of Muzzle Blasts magazine.

arcticap
August 26, 2008, 05:01 AM
They list a 20 inch Blunderbus barrel with breechplug installed in 12 ga., 10 ga. & 4 ga. in steel for $215 or call for the price of a brass one.

http://www.stonewallcreekoutfitters.com/w_e_rayle_rifle_barrels.htm

The Rifle Shoppe sells several authentic Blunderbus parts kits and states to buy the [shorter] barrel separately from Ben Coogle or Getz. They should be able to help you locate either maker if you really wanted to.

http://therifleshoppe.com/(822).htm

http://therifleshoppe.com/(821).htm

Since you have the machining skills, why use this tubing and not just machine your own flared blunderbus barrel?
Will you lose very much barrel wall thickness when threading the breech?
Will you need to machine your own breechplug?
In relation to barrel steel, what is DOM tubing?

Good luck with whatever you decide to do. :)

wulf
August 26, 2008, 05:32 AM
If you are going to invest the time and money (especially the time) in a project then you might want to do it right. There are blunderbus barrels and kits available in brass or steel that follow (mostly) original examples. A common late type of blunderbus was fashioned along Brown Bess lines with a large Tower or Grice lock and other BB hardware. Do the research so you end up with exactly what you want.

Omnivore
August 27, 2008, 10:51 PM
Yak is a machinist. Barrel makers are machinists...

Yak; I don't know your skill level or experience, but it's not a complicated job. I'd be concerned about the strength of the DOM tubing though. What alloy? What tensile strength, hardness? Good barrel steel is a 4140 class-- super strong, holds up to heat, and not too brittle. One failure and you'll pay for the experiment with the loss of body parts, as was known to happen back in the day. Hell, it happens now with modern guns, modern alloys and modern manufacturing methods.

Some of the farmers around here have made BP field pieces out of heavy farm implement axels-- again, very good steel, and they over-engineer them.

yakkingallover
August 27, 2008, 11:48 PM
Thanks for the responses, as far as building one verses buying one, the idea was a time occupying project not a lack of availability. I have looked at the dimensions of production barrels and by all means what I have selected should be much stronger.Omnivore I have been an automotive machinist and general fabricator for about 8 years now my initial selection of material was based on the fact that DOM is a seamless tubing which I saw as ideal for barrel making, I am researching the exact alloy currently and was glad you mentioned 4140 as that was the type of answer I was looking for as far as materials go. The piece of tubing I have is 1" i.d. and .250 wall thickness which is usually used for roll cages and custom steering assemblies. I will do more research before I risk losing any limbs. Thanks again for everyones help and any other comments or criticisms are more than welcome...

Tinker2
August 28, 2008, 07:13 PM
From what I have found by looking into the same idea.

DOM (Drawn Over Mandrel) is welded steel round tubing made
to LOOK seamless.

It is not made to take the pressure that that is created when
a gun goes off, it made for a slower build up of pressure.

As I understand it they can spilt alongside or parallel to
the weld on the “seamless” DOM.

I would like to see someone do some blowup tests just
to see how good/bad they truly are.

No professionals will use it, that I know of.

Tinker2

arcticap
August 28, 2008, 09:07 PM
After reading the thread about the bursting of the Indian made gun and the mere mention of DOM tubing, I tried to looked up the spec's for DOM tubing on a manufacturer's website.
While I'm sure that there's many different types, compositions and strengths of DOM tubing, the chart linked below mentions that 1 inch DOM stainless steel tubing that's .25 inches thick has a burst pressure rating of 3,750 PSI.
According to the chart, the DOM tubing that the chart lists would need to have a wall thickness many times greater than .25 inches in order to meet even the minimum proof standards that have been mentioned in several previous threads which discuss the barrel integrity of Spanish, Indian & British guns.
I still don't know exactly which kind of DOM tubing is being considered for use as a blunderbus barrel, but there should be serious consideration given to its actual strength rather than its perceived strength.
What is the actual burst pressure rating of the DOM tubing that is intended to be used?

http://www.greenvilletube.com/steel_tube_PSI.htm

scrat
August 28, 2008, 09:28 PM
In other words. buy a barrel.

Wow that would be a hard lesson earned. goo for looking up arcticap

Tinker2
August 28, 2008, 10:34 PM
arcticap

I think you missed a decimal point, .025
The burst pressure rating is higher for .25

My glass topped coffee table will hold a lot pounds
but if I drop something on it, it breaks.

I am not any expert on this.


Tinker2

ltetmhs
August 28, 2008, 11:16 PM
What about contacting a custom barrel maker and see if he can hook you up with his source for his steel? They might not tell you or maybe they would sell you just the steel? I don't really know how that would work but thats where I would start. I too am constantly trying to find time occupying projects.

yakkingallover
August 28, 2008, 11:44 PM
That answered my questions I will research further and reconsider all plans. I have been shrapneled before and don't wish to repeat that experience. This is why I came to the High Road...

Tinker2
August 29, 2008, 12:26 PM
when I make a barrel for black powder I use 12L14 steel.
It is what most of the barrel maker use, I think.



Tinker2

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