wrought iron barrel min. wall thickness

[bob in the woods]

I have been doing my best with making a barrel from a nice piece of 19th C wrought iron.
So far, so good.  I'm wondering how to determine how large a bore I can clean it up to ?
The OD is close to 1 inch, [ still in the round ]  but I wonder how you can determine the wall thickness along the length of the tube ?  It looks pretty straight , but ??   I was hoping for at least a .54 or there about .  I'm going to have to make some twist drills and a reamer, but this is a long term project..I'm in no hurry.

[Dave B]

I have played around with some barrel making with pistols and you dont have enough meat with a 1" round stock to make a .54 cal bore if your going for an octagonal profile. If you draw a 1: circle then draw in your flats now in the middle of that draw a .54 circle. Your breach plug will need to be a 3/4" bolt thread. I should think you could pull off a .45 possibly .50.  I know that they use bar stock that is at lease 1 1/4" to make a 1" octagon barrel. I cant speak for minimum wrought Iron barrel thickness other than seeing some originals and they have breaches of 1" or greater for .54 cal in octagon profile. The breach pin threads did not but up against a rim but was just over bore size to seal the breach. Sounds like a cool project.

[bob in the woods]

Sorry if I wasn't clear re the barrel profile. It is still in the round, but I'll be hammering it to a rough octagon before draw filing, so I don't think I'll lose too much material in the process.

[rich pierce]

Wall thickness at the middle of the flats is smaller when octagonal is made from round. Wall thickness at the corners is greater when round is formed to octagon.

[Dave B]

If your dumping up the breach first to over size then going for the octagon that works. You will lose some material due to slag.

[James Wilson Everett]

Guys,

Here is a link on how to measure the barrel wall thickness in the middle.  If you make your own barrels, this tool is a necessity.  The barrel in the topic is a forge welded wrought iron barrel, 0.513 bore at the muzzle (slightly larger at the breech), the breech is 1.08 across flats.

 https://americanlongrifles.org/forum/index.php?topic=21868.msg208506#msg208506

Jim

[Clint]

If you hammer a one inch r b down to eight sides you can expect to arrive at 3/4 " across the flats. If you could find some one inch square bar , it would be much easier to get a barrel size. Bear in mind, the iron needs to be much hotter that a steel forging in order to avoid shaking the fibers. I always start forging old iron at welding temps, because I assume that the original forging was finished at lower temps and thus is set up to split. A split does not need to be a big visible crack, only a small grey for fouling and high pressure to prey on. One inch stuff can be found as old fence posts.

[bob in the woods]

Guys,

Here is a link on how to measure the barrel wall thickness in the middle.  If you make your own barrels, this tool is a necessity.  The barrel in the topic is a forge welded wrought iron barrel, 0.513 bore at the muzzle (slightly larger at the breech), the breech is 1.08 across flats.

 https://americanlongrifles.org/forum/index.php?topic=21868.msg208506#msg208506

Jim
Thank you very much .  That is exactly what I needed to know !

[Hungry Horse]

I will just say this, wrought iron comes in a myriad of different compositions ranging from quite pure, to riddled with impurities, and is no longer manufactured in the U.S. Barrel makers of the past rarely made barrels to minimum dimensions for safety reasons. The legendary swamped barrel, that barrel makers today emulate was designed to make the gun less muzzle heavy, and put the minimum barrel thickness part as far away from your face as possible. If wrought iron could be depended on to contain the high pressures generated at ignition, don’t you think the early gunsmiths would have simply made a thinner barrels? I admire your effort, and admire your willingness to attempt this hard, dirty, tedious, work. Good luck, and be safe.

  Hungry Horse

[jerrywh]

One thing about modern steel is it is reasonably uniform in structure. All wrought iron is not equal. Most all wrought iron barrels were pretty hefty.  I don't think you have enough material there for a 54 cal. 

[Jim Kibler]

Yes.  Wrought iron is prone to having defects.  Slag stringers, present in all wrought iron, reaching a critical size can be considered a defect.  People debate barrel material, but the biggest concern in my view is potential defects in the material.  I've seen barrels made from wrought iron that were deep hole drilled and made using modern techniques.  Some of these had large slag stringers visible to the naked eye that I would in no way trust.  So, what I'm trying to say, is beware of wrought iron.  Some may be just fine, but some may be totally inadequate.  Also question your ability to determine what is okay and what is not. 

Jim

[bob in the woods]

No matter what, I will proof it with a double charge and two balls. It will be a smoothbore.

[David R. Pennington]

Bob, did you weld this barrel up around a mandrel out of bar stock? I was fascinated with the technique of forge welding a gun barrel as it seemed almost an impossibility to me, so I had to try it. Working with a friend who does blacksmithing at a local museum we welded one up out of buggy tires. We had several wagon tires but the best grade wrought iron we found were these smaller buggy tires. They weren’t large enough for rifle barrel blanks so we took two three foot long pieces and welded them together road side to road side to get a heavier skelp to start with. We welded them in my friends shop where he has a power hammer. This iron welded beautifully and the two pieces would stick together in the fire while heating. We did most of the actual barrel welding at the museum forge with a traditional set up with bellows.
What I learned in the process was that as you weld and forge, the iron is compressed more tightly toward the center around the mandrel and so less likely to have a flaw near the center than on the outside. Flaws on the outside are easily detected and repaired.
Also wrought iron is a forgiving material. It will withstand higher temps without burning and flaws and problems can be corrected. You can selectively heat and bump more material into areas where you need it. Ours grew as we welded. We started with three feet and ended up with almost five feet! It got difficult to manage in the fire so we ended up cutting it into two blanks. We don’t have a barrel bored yet, hopefully soon. I built a boring bench, but the project kind of stalled out for the moment. Good luck on your project and keep us posted.

[bob in the woods]

David, that is an awesome project.  Yes, I made the barrel up but mine is only pistol size. 
I'm interested to see how your boring goes, so keep us up to date on that please !   You will be faced with exactly what I wanted to know..ie  cleaning up the bore    Will you be forging that barrel octagon, or leaving it round ?

[mark brier]

How about try finishing all the forging first and answer your own question. Such confusion, the way you wrote it makes me think you want to ream it out and then hammer it octagon. You need to plan for such things in the beginning . What size was the skelp? Mandrel sizes?

David. Glad your still working on your project, but a growth of that much sounds like way to much hammering. I think the most I have had a piece grow was about 7 inches. Just the first few hits and your done welding continuing to hammer is just thinning and lengthening and probably setting up hot shuts.
Mark Brier

[bob in the woods]

Next thing I need to do is to hammer the barrel to octagon.  Then I will drill / ream it out.
I'll rephrase my question .  Does  wrought iron  generally require a greater wall thickness as a standard practice compared to the material used in commonly available modern muzzleloading barrels , such as Colerain or Getz ?   From many measurements listed in RCA , comparing outer barrel dimensions to bore size, this does not appear to be the case.   Living where I do, I really haven't had an opportunity to see more than a couple of wrought iron barrels and they weren't in great shape.

[David R. Pennington]

Bob, we actually did start working in the flats since that photo was taken, just don’t have a photo.

Mark, to clear up your growth question: the growth occurred over both processes; welding the two pieces of tire together to form the skelp (with power hammer help) and welding the barrel. We anticipated growth on barrel welding. Aiming for around a 40” barrel we started with 36” stock pieces. We didn’t anticipate how much the skelp would grow welding the two sections together. Remember this was our first attempt. Hindsight, I would have trimmed skelp before beginning to weld barrel.

[Hungry Horse]

 I found that specific applications warranted different degrees of quality in the days of wrought iron. I found as was stated earlier that iron tires from heavy freight wagons were often of rather poor quality, but interestingly the hub rings from the same wheel were much better quality. An old building in our town had heavy wooden awnings on two sides supported with long wrought iron rods. These were of excellent quality, but some of the other building hardware was terrible, and so full of impurities that when the paint was removed the metal parts looked like they had been I embossed with wood grain. Budding barrel makers using wrought iron should be very careful about the quality of the wrought iron they intend to make a barrel from.
 With much time, heat, and hammering, poor wrought irons quality can be improved to some degree, but its easier to start with a higher quality wrought iron to begin with, because there is plenty of heating, and beating, in making a barrel.

   Hungry Horse

[David R. Pennington]

What you said Hungry Horse, about different grades of wrought. I had one piece from an old plow brace that reminded me of cold spaghetti stuck together. I had to continually weld loose ends together. I had some bar stock from an old door brace that was beautiful to weld hatchets up with, using plow steel sandwiched in.

[bob in the woods]

The wrought iron I'm using came from Brad Emig , Cabin Creek some 20 years ago. I've used pieces of this over the years for triggers , sights, hatchet etc and it is top quality stuff.  Brad was selling wrought iron barrels for a while which were bored  rather than forged. I don't know if they are still available or not.

[David R. Pennington]

Bob, I don’t think you ever really got an answer to your original question on wall thickness did you? I don’t really know the answer. If I ever get a barrel completed I will certainly proof test it thoroughly before stocking. I bought a new old stock barrel from 1970’s a while back. I made a forged iron breech plug for it and proofed it well before stocking it.