Those in the know?
- Thread starter Brutus
- Start date
You would have to check Machinery's Handbook or some similar source for the tensile strength of bronze vs brass. I suspect that as long as you were not trying to build to minimum dimensions, it would not make a lot of difference
cheers mooncoon
cheers mooncoon
Bronze over brass, if you have the choice.
If you can get actual alloy numbers, it would be a big help in determining exacts rather than estimates.
Brass is fairly easy to cast, and machines easy, bronze is decent to cast, and is much tougher to machine.
Cheers
Trev
If you can get actual alloy numbers, it would be a big help in determining exacts rather than estimates.
Brass is fairly easy to cast, and machines easy, bronze is decent to cast, and is much tougher to machine.
Cheers
Trev
There are US barrel makers who have made "brass" barrels. Might be an idea to ask on one of the US muzzleloading forums.
There are all sorts of copper based alloys, with varying properties. Not only is tensile strength an issue, reaction to pressure spikes is critical.
With cast metal, there is always the risk of voids in the casting. Machined from solid might be preferable.
Some time ago, I asked a similar question about brass barrels, thinking in terms of a blunderbuss. It was suggested then that bronze would be better than brass.
Might be worth spending some time with Machinery's Handbook, metal manufacturers' and distributors' catalogues.
There are all sorts of copper based alloys, with varying properties. Not only is tensile strength an issue, reaction to pressure spikes is critical.
With cast metal, there is always the risk of voids in the casting. Machined from solid might be preferable.
Some time ago, I asked a similar question about brass barrels, thinking in terms of a blunderbuss. It was suggested then that bronze would be better than brass.
Might be worth spending some time with Machinery's Handbook, metal manufacturers' and distributors' catalogues.
Halger280HVMag
CGN Ultra frequent flyer
- Location
- B.C. XMU Local .454
FWIW.
Copper/Zinc=Brass
Copper/Tin=Bronze
Bronze is stronger than Brass and was used in casting some ship's guns .
The crystaline structure is different.
Brass is more brittle, Bronze has more spring.
A Bronze gun is less likely to grenade, than a Brass gun.
The Zinc present in Brass, makes Brass extremely sensitive to salt water corrosion.
The Tin present in Bronze, makes Bronze corrosion resistant.
It also makes Bronze a tougher material than Brass.
On the lathe, Brass falls from the tool in a shower of tiny chips.
Bronze tends to form a long, tough, thread-like chip.
Using the same round nosed tool bit.
Bronze is available, in the form of shafting of various diameters.
I have built a few, using that material.
Personally I'd pay a bit more if needed, and go Bronze.
I want to hear the gun go BOOM.
Not KA-BOOOM Eh!
Copper/Zinc=Brass
Copper/Tin=Bronze
Bronze is stronger than Brass and was used in casting some ship's guns .
The crystaline structure is different.
Brass is more brittle, Bronze has more spring.
A Bronze gun is less likely to grenade, than a Brass gun.
The Zinc present in Brass, makes Brass extremely sensitive to salt water corrosion.
The Tin present in Bronze, makes Bronze corrosion resistant.
It also makes Bronze a tougher material than Brass.
On the lathe, Brass falls from the tool in a shower of tiny chips.
Bronze tends to form a long, tough, thread-like chip.
Using the same round nosed tool bit.
Bronze is available, in the form of shafting of various diameters.
I have built a few, using that material.
Personally I'd pay a bit more if needed, and go Bronze.
I want to hear the gun go BOOM.
Not KA-BOOOM Eh!
When artillery and ships' guns were being cast, the ratio of Gunmetal (a particular alloy of Bronze) to Weight of Shot was 100 to 1: a 1-pounder barrel would require 100 pounds of bronze.
The formula for Iron guns was 300 to 1.
Check out those old coastal guns and the ones in your local fortifications. If they are British guns, they all are marked with the Tube Weight in Hundredweights (112 lbs eah), Quarters (28 lbs) and Pounds.
Some strange but marvellous things have been accomplished with Brass. Felix Werder of Zurich made brass barrels 400 years ago which were not much thicker than a matchbook cover and yet would pass the same Proof Test as an iron barrel. His secret was a cast- brass barrel which was COLD-FORGED to final shape and dimensions: a LOT of work.
There is a lot to learn.
My Pocket Reference lists more than 60 common compositions for Brass, the same for Bronze and page after page of Steels. Machinery's Handbook has more and it has a lot more detail regarding strength and other properties. There should also be good information available from the various manufacturers, especially in the case of iron alloys.
.
The formula for Iron guns was 300 to 1.
Check out those old coastal guns and the ones in your local fortifications. If they are British guns, they all are marked with the Tube Weight in Hundredweights (112 lbs eah), Quarters (28 lbs) and Pounds.
Some strange but marvellous things have been accomplished with Brass. Felix Werder of Zurich made brass barrels 400 years ago which were not much thicker than a matchbook cover and yet would pass the same Proof Test as an iron barrel. His secret was a cast- brass barrel which was COLD-FORGED to final shape and dimensions: a LOT of work.
There is a lot to learn.
My Pocket Reference lists more than 60 common compositions for Brass, the same for Bronze and page after page of Steels. Machinery's Handbook has more and it has a lot more detail regarding strength and other properties. There should also be good information available from the various manufacturers, especially in the case of iron alloys.
.
Yeah. Without the actual alloy, or a means to test a sample of the material, its all a huge guess.
The traditional tags of brass (copper zinc alloy) and bronze (copper tin mixes) are often barely adequate to define any of the many many different copper based alloys out there, many of which cross the lines of what would be called the other, if those mixtures were held to as definitive.
Aside from zinc and tin, other common alloy ingredients are aluminum, nickel, and beryllium, for various properties, among others.
Not as clear cut as it should be. Highlights the need to know what alloy was used, and who made the material, and how it was made and treated along the way.
Cheers
Trev
The traditional tags of brass (copper zinc alloy) and bronze (copper tin mixes) are often barely adequate to define any of the many many different copper based alloys out there, many of which cross the lines of what would be called the other, if those mixtures were held to as definitive.
Aside from zinc and tin, other common alloy ingredients are aluminum, nickel, and beryllium, for various properties, among others.
Not as clear cut as it should be. Highlights the need to know what alloy was used, and who made the material, and how it was made and treated along the way.
Cheers
Trev
Common Cartridge Brass is supposed to be 70Cu/30Zn by weight. Norma advertises that they use 72/28 for longer-lasting "better" brass and it is known for SURE that some manufacturers have departed from this in the other direction, turning out garbage that won't last a single firing. The standard composition makes an alloy which is easy to draw; that's why it is used. It also casts pretty good, but likely you will need more Copper for strength.
SOME types of Brass go as high as 85Cu/15Zn, giving a different colour and completely different casting and machining characteristics.
Might be best to start with an alloy you KNOW, then make your mods as the metal is being melted.
If you are casting your barrel, be sure to do it with the MUZZLE UP..... and the longest forward section you can get in front of the Muzzle: at least a foot. The more WEIGHT of metal per area unit, the less chance you will have of SPONGY brass. You REALLY don't want to be holding onto something with a spongy barrel when it decides to let go!
Check your bore diameter when it is finished and PROVE the barrel properly before assembling it to a gun. There is a set of the old English Proof tables in the back of the Dixie catalogue. Some of the Proof loads were based on double powder/double ball at the SAME TIME; your working load was half the powder and half the weight of shot. If a barrel will withstand the old English Proofs, chances are that it's pretty safe for murdering tin cans with.
Hope this helps.
.
SOME types of Brass go as high as 85Cu/15Zn, giving a different colour and completely different casting and machining characteristics.
Might be best to start with an alloy you KNOW, then make your mods as the metal is being melted.
If you are casting your barrel, be sure to do it with the MUZZLE UP..... and the longest forward section you can get in front of the Muzzle: at least a foot. The more WEIGHT of metal per area unit, the less chance you will have of SPONGY brass. You REALLY don't want to be holding onto something with a spongy barrel when it decides to let go!
Check your bore diameter when it is finished and PROVE the barrel properly before assembling it to a gun. There is a set of the old English Proof tables in the back of the Dixie catalogue. Some of the Proof loads were based on double powder/double ball at the SAME TIME; your working load was half the powder and half the weight of shot. If a barrel will withstand the old English Proofs, chances are that it's pretty safe for murdering tin cans with.
Hope this helps.
.
Original cast gun tubes had a disconcerting habit of occasionally bursting. Both iron and brass.
I'm not aware of any modern foundries casting barrels for small arms. The cannon being made these days tend to have steel sleeves installed.
If I were to make a brass/bronze blunderbuss barrel, I would be inclined to prefer bored from solid, rather than cast. After a very careful study of the catalogue of available metals. And would only use it after serious testing.
I have no idea of the alloy or methods used to produce brass barrels in India. Might be very modern. Might be very old technology. Also have no idea what QC or testing methods are employed. Probably the bottom line is that if it survived proof testing it survived proof testing. Which probably means there were no serious flaws or honeycombs.
I'm not aware of any modern foundries casting barrels for small arms. The cannon being made these days tend to have steel sleeves installed.
If I were to make a brass/bronze blunderbuss barrel, I would be inclined to prefer bored from solid, rather than cast. After a very careful study of the catalogue of available metals. And would only use it after serious testing.
I have no idea of the alloy or methods used to produce brass barrels in India. Might be very modern. Might be very old technology. Also have no idea what QC or testing methods are employed. Probably the bottom line is that if it survived proof testing it survived proof testing. Which probably means there were no serious flaws or honeycombs.
The british proof loads were a provisional proof load of 4 x powder plus 1 charge of shot (sort of) when the barrel was still fairly rough. The definitive proof was 2 x powder plus 1 charge shot (sort of) and was done when the barrel was in its finished state. about 5% of barrels failed. The sort of refers to the projectile was not shot but a ball or cylinder of a specified weight. (which was close to the service weight of projectile) I am not sure just how close to bore dimensions the proof projectile was.
My comments are based on the proof tables in the back of WW Greener's "the Gun"
cheers mooncoon
Friend TIRIAQ likely has the best idea: start with new solid stock and machine the barrel.
It might be more expensive in the short run, but how much is your left arm worth? The new metal will at least be of a KNOWN composition and it SHOULD be free of voids. If there actually are any, they ought to show on machining.
Proof loads were generally by the BORE of the gun and the early tables were set up for GAUGE (number of balls to the pound of that size barrel). Proof for smoothbores changed over the centuries and was different than for rifles.
I think the set in the Dixie catalogue might predate Greener's book; I haven't looked at them in a long time. But they are there and the Dixie book is available readily, which is why I used that reference. My edition of Greener is a reissue of the 1910 version; it went through many editions.
.
It might be more expensive in the short run, but how much is your left arm worth? The new metal will at least be of a KNOWN composition and it SHOULD be free of voids. If there actually are any, they ought to show on machining.
Proof loads were generally by the BORE of the gun and the early tables were set up for GAUGE (number of balls to the pound of that size barrel). Proof for smoothbores changed over the centuries and was different than for rifles.
I think the set in the Dixie catalogue might predate Greener's book; I haven't looked at them in a long time. But they are there and the Dixie book is available readily, which is why I used that reference. My edition of Greener is a reissue of the 1910 version; it went through many editions.
.
I've been pondering the machining of a blunderbuss barrel for a while. External profiling, with either a tapered octagon to round breech, or plain round is straightforeward enough. Drilling and reaming the parallel section of the bore is conventional.
To produce the internal flare, more or less paralleling the exterior, would take a bit of ciphering. Perhaps a series of cuts could be made with the compound, complementing the external contour. The series of taper cuts could be blended into a smooth curve. I wonder if original makers used a purpose made contoured reamer to finish the curved portion.
Just did a bit of googling for bronze barstock. Lots of choices. Solid and tube.
To produce the internal flare, more or less paralleling the exterior, would take a bit of ciphering. Perhaps a series of cuts could be made with the compound, complementing the external contour. The series of taper cuts could be blended into a smooth curve. I wonder if original makers used a purpose made contoured reamer to finish the curved portion.
Just did a bit of googling for bronze barstock. Lots of choices. Solid and tube.
I am wondering if you could form the flare by annealing the muzzle area and forcing a steel cone in while spinning the barrel in the lathe. I would expect it to take quite a few annealings and formings to accomplish and you would probably want to start with the barrel a couple of inches too long so you could do a practice run first
cheers mooncoon
cheers mooncoon
You two ought to get out more.
Brass, you wont likely get to flare worth a darn, bronze, you would do better forging hot.
But for the contours, your best and easiest route is to take a good look at a tracer unit for a lathe, and see how the template can be used to provide a very reasonable way to turn an inside profile.
Not a tough job to rig up.
Even if you only rigged a pointer that could be used to follow a drawing, it would allow enough accuracy down hole, to be able to get close enough to blend the cuts together smoothly.
My suspicion, based on readings about the turners trades in England, is that the flared barrels would have been cast to size, then cleaned up by a turner working freehand with a hand held tool, similar to wood turning. That would have minimized the amount of lost material, and provided the best product with the least work.
We are spoiled for choices, when it comes to available tools and materials now.
Another cheap accurate way to machine the flare, would be to build or buy a radius attachment large enough to cut what was desired. By changing the arc center point, and the radius, a pretty fair flare could be machined repeatedly.
I suspect that this all has wandered rather far away from Brutus' original question, too.
Cheers
Trev
Brass, you wont likely get to flare worth a darn, bronze, you would do better forging hot.
But for the contours, your best and easiest route is to take a good look at a tracer unit for a lathe, and see how the template can be used to provide a very reasonable way to turn an inside profile.
Not a tough job to rig up.
Even if you only rigged a pointer that could be used to follow a drawing, it would allow enough accuracy down hole, to be able to get close enough to blend the cuts together smoothly.
My suspicion, based on readings about the turners trades in England, is that the flared barrels would have been cast to size, then cleaned up by a turner working freehand with a hand held tool, similar to wood turning. That would have minimized the amount of lost material, and provided the best product with the least work.
We are spoiled for choices, when it comes to available tools and materials now.
Another cheap accurate way to machine the flare, would be to build or buy a radius attachment large enough to cut what was desired. By changing the arc center point, and the radius, a pretty fair flare could be machined repeatedly.
I suspect that this all has wandered rather far away from Brutus' original question, too.
Cheers
Trev
Ages ago, I was doing some research, and came across references to "aluminum bronze" as being a superior alloy. When I was googling, its there, available in 24" tubes, 3/4" ID, 1 1/4" or 1 1/2" OD. Many other sizes, this would be the most useful, 1"ID next. That is 4ga, as opposed to 11ish. Didn't inquire about prices.
Nothing to do with barrels, but 40 years ago, when I was involved with the manufacture of repro NW guns, we were having the parts investment cast. The foundry did not cast the serpents in "brass". They used a "bronze", which they felt was much easier to cast. Can't tell by looking at it.
trevj - a pointer and a template could certainly be used to freehand the flared bore. Most of the metal could be hogged out, and the finishing done in reference to the template.
Nothing to do with barrels, but 40 years ago, when I was involved with the manufacture of repro NW guns, we were having the parts investment cast. The foundry did not cast the serpents in "brass". They used a "bronze", which they felt was much easier to cast. Can't tell by looking at it.
trevj - a pointer and a template could certainly be used to freehand the flared bore. Most of the metal could be hogged out, and the finishing done in reference to the template.
