Why did they use octagon barrels so much?

[MBTcustom]

It's a question that has bugged me for years, and I honestly dont have a good theory on this. I would like to know why so many of the guns from around the turn of the last century have octagon barrels?
It seems to me that it made the manufacture of the guns harder and more costly without aiding production in any way.
Where those barrels considered better for heat dissipation?
Was it easier for the rifling process?
I know that in this era, octagon barrels are just for looks, but what was the original reason?
If anybody has a definitive answer I would love to know. I have theories by the bushel basket, but I don't know why they did this, any body care to elaborate?

[sbowers]

Because the barrel blanks came in the octogan configuration from the steel makers and it was more expesinve to turn them to round than leave them as recieved and drill and rifle them.
Steve

[Uncle Jimbo]

I can only venture a guess same as you. I always thought that the quality of the steel at the time dictated more material around the bullet.
I can tell you this, I have and always will love the look of the octagon barrels on lever guns and some of the older style single shots.

[waksupi]

A carry over from forged barrels. It is a lot easier to forge an octagon barrel, than a round barrel. They were forged around a mandrel, which also formed the rough bore when withdrawn. As to why they carried over after more modern iron working methods were developed, I'm not sure. I suspect it was preference, and tradition. Barrel blanks never came as octagons, I've seen semi truck loads of barrel stock, and those truck loads turned into barrels. It's all round stock. The old ones were forged octagon, the modern ones are milled to shape after being bored and rifled.

[Chicken Thief]

Hammer forging.
First square then octagon.
Thus no hex!
Round is way more work.

[John Taylor]

A lot of the old gunsmiths were small back yard shops during the muzzle days. A barrel could be made from flat wrought iron and welded full length and at the same time be hammered into an octagon shape. A lathe for turning something round was not something a small shop would have. The barrel was draw filed to make the flats smooth. Bottom three flats were not draw filed usually. Tradition carried over to the more modern cartridge guns and a lot of people still wanted octagon barrels so most company went with what was selling. Something in the octagon shape seem to attract buyers. Even when Remington was making cast barrels they sold octagon barrels to the back yard gunsmiths to build rifles. Most companies making military barrels were large enough to afford the equipment to make round barrels.

[Longwood]

I have read a lot about hammer forging and hammer welding barrels. They came out round unless they were being forged from a block then drilled.
Hammer forging was often used to form blocks into long thin flat bars before the hammer welding process.
I never heard of anyone going to as much trouble as it would be to make a round barrel into an hexagon or octagon.
Most of the octagon etc, rifle barrels were in that configuration because that is how the steel came from the mills. I think the old timers also knew thy look better.
Have you ever seen a long rifle that has a flat filed barrel that looks like a long octagon trumpet?

[Jim Flinchbaugh]

First square then octagon.

Yup!
Octagon barrel is just a square barrel with the corners cut off

[longbow]

While I agree with the hammer forging an octagonal barrel likely being easier than round there were also a number of round barrels produced in the hand forging days:

- fowlers both single and double barrel
- military muskets by the thousands like Brown Bess, Charleville Muskets, Zouave, trade muskets, etc.

The military wouldn't be too concerned with any extra work or cost if the round barrel was lighter of better but common folks would be as would the Indian traders yet I think all common smoothbore trade muskets were round barrel.

I used to think octagonal barrels were made to help index for rifling but any old wooden rifling benches I have seen do not require the barrel to be rotated, The rifling drum is rotated and indexed with pins or slots.

So I guess it is kind of obvious I don't have a good answer for this!

Now you got me thinking I better try to find out.

Longbow

[just.don]

A carry over from forged barrels. It is a lot easier to forge an octagon barrel, than a round barrel. They were forged around a mandrel, which also formed the rough bore when withdrawn. As to why they carried over after more modern iron working methods were developed, I'm not sure. I suspect it was preference, and tradition. .

+1
Read the foxfire book on gun making. very informative.

[L Ross]

Any of you fellers ever do any black smithing? Have you ever seen a swedge block?

Duke

[MBTcustom]

While I agree with the hammer forging an octagonal barrel likely being easier than round there were also a number of round barrels produced in the hand forging days:

- fowlers both single and double barrel
- military muskets by the thousands like Brown Bess, Charleville Muskets, Zouave, trade muskets, etc.

This was why I asked my original question. Throughout the ages, there have been guns made with either round or octagonal barrels, both by hand with a forge, and after the advent of steel mills and metal lathes.

Any of you fellers ever do any black smithing? Have you ever seen a swedge block?

I have done a lot of blacksmithing with a coal forge. I know what a swedge block is, but it could be used to make either round or hex stock fairly easily. That just makes the question even more interesting and the answers more vague.

I think the old timers also knew thy look better.

This could be the best answer.

[wv109323]

I saw a guy making modern day muzzleloaders at a fair.. The vise that he used to rifle the barrel clamped the barrel on the flats of the octagon barrel. To equally space four riflings( actually lands) in the barrel the barrel was rotated 1/4 turn or two flats of the barrel and reclamped in the vise.
The rifling machine that this gentlemen had cut one land at a time with a hook type bit. The mandel that held the bit was twisted with the desired rate of twist. As the hook was pulled through the barrel the mandrel was pulled through a stationary eye that caused the hook to cut a spiral land.
I don't know why a smoothbore would have an octagon barrel unless as already mentioned. Looks and a common shape to forge raw material.

[longbow]

Maybe you have something there. Like I said, I first thought that the flats were not only easier to make than round because you can rough hammer to shape while forging then draw file to smooth and even up flats. Then they make the perfect indexing for 4 or 8 groove rifling, but... so far I haven't seen a rifling bench that used the barrel rotation to index. Not to say it wasn't done or maybe that's how it all started out because it seems that octagon barrels were most common with rifled barrels rather than smoothbores. At least in my limited experience.

Now having said that, some smoothbores had part octagon and part round barrels. Doh!

Thin round musket barrels would be lighter for sure so easier to carry. Imagine a Brown Bess with a 75 cal. octagon barrel. Yikes! You'd need a winch to get it up to your shoulder.

The larger bores also typically run at lower pressures so maybe part of it is the need for thicker barrel for smaller bore rifles, wall thickness for dovetails for sights (hard to dovetail a thin round barrel and hard to drift a soldered sight), ease of forging, indexing for rifling... did I miss anything? Oh, good looks. I know I am grasping at straws here.

There has to be some good explanations because the old guys didn't do it just because.

Ease of manufacture, extra wall thickness for dovetails and indexing for rifling all make sense.

It may well be a combination of several things that made octagon easier to make then tradition that carried it on afterwards.

Look at Damascus barrels. While they look good, they are not as sound as machined from solid stock barrels yet after the days of hand forging and Damascus there were shotgun (not sure about rifle) barrels made with faux Damascus patterns to look like Damascus.

Okay, I will quit rambling here because I really don't know.

Longbow

[rockrat]

Yup, have a swedge block

[Longwood]

We have sort of lumped a few thing into one.
Hammer forging is mainly making a hunk of steel or iron into a different shape. I could be square or about any shape they wanted to make. Machines made round, hex and octagon with much cheaper machines than round stock. Square stock was the most plentiful but many mills made rods of more shapes.
Hammer welding which is sometimes referred to as Damascus is how they made thin walled barrels by wrapping bands of steel around a mandrel and hammer welding them together. For stronger and fancier looks, three or more bands would sometimes be twisted and hammer welded into one then wrapped and welded around a mandrel. The better smiths making more expensive barrels could do wonders with the process. I have seen where they did three into three into three rods into one flat bar before using it to make a barrel. That type of gun is in a museum somewhere. The man hours to make a barrel that way must have been immense.

[Longwood]

Not to Hihack the thread

I read a book years ago about some of the legendary Samurai sword of Ancient Japan.
They were made by drawing out then folding bars of steel back over themselves and hammer welding them together over and over, doubling the layer count each time until some swords had one million layers of steel.
They did it with three men on sledge hammers and one holding the blade. I saw a video once and it sounded like a machine making the sword.
Forging steel smashes the molecules together making the steel harder and tougher.
Some of the blades were not only legendary but had names and the few that survived our governments orders to destroy all of them, are collector Items worth millions of dollars.
One in particular was named the beard cutter because when they tested it on a prisoner by cutting him in two at the shoulders, it was so sharp, it also cleanly cut the prisoners long beard.
Another supposedly well documented story I read about the swords was when two rival Samurai met on the street one day. One cut the other one in two pieces up through the hip bone and out through the opposite shoulder blade "AS" he drew his sword. The move has a name and was practiced often on prisoners.

[longbow]

True enough. What we typically call "Damascus" steel is pattern welded steel and can be made to produce many different patterns by mixing material and twists then etching with acid after finishing to bring out the pattern. That is the artwork of Damascus and probably why faux Damascus was often used on machine made steel shotgun barrels.

Barrels were also made by simply forging flat bar around a mandrel then forge welding at the seam which ran full length down the barrel. A process very similar to seam welded pipe using skelp strips around a mandrel. Nothing too fancy about that. I have to guess that was the "economy" barrel version of its day. Not sure if the seam was oriented to a flat or corner of an octagonal barrel. If to a corner then there would be a little more material there so maybe a little stronger?

Longbow

[halfslow]

I always thought it was because of the primitive tools used by most makers in the old days.
It is far easier to file a smooth and straight flat with a file you made this morning than turn a uniform taper without ripples. All you need is good and straight guide rails, and an apprentice with patience.
It became the way rifle barrels must be made.
All forged finishes I ever saw looked like a blacksmith made it with a hammer.

[perotter]

It is far easier to file a smooth and straight flat with a file you made this morning than turn a uniform taper without ripples. All you need is good and straight guide rails, and an apprentice with patience.

Also, some used to grind the flats with a grindstone that was water powdered. Basically they put the barrel in a guide and let gravity fed the barrel down into the grindstone. This was an old time automation method that was slow, but didn't require any labor.