safety of brass barrels

[hyltoto]

It just struck me reading the post below about the brass barrel, how did they avoid the brittleness that comes from work hardening? Is a brass barrel something you would want anneal periodically?

We had a machine at work that required an automatic brushing to remove char and scale. The steel brush was abrading the tooling so the young pup engineer bought a brass one. It worked well untill the bristles work hardened and became brittle. A young lady operating the machine had a bristle bury itself in the end of her nose about half inch deep.

[Ezra]

That's taking the tough route to nose piercing...


Ez

[Levy]

I know nothing about the safety of modern barrels being made out of brass or bronze or whatever alloy it is, but I would like to have one.  I don't know if this pertains or not but I preserved a brass/gun metal cannon from the early 1600s and the breech end of it was a spiderweb of tiny cracks (behind the trunnions).  The muzzle portion of the barrel was not cracked (forward of the trunnions).  I assumed that the cracks in the breech end were due to firing which caused expansion and contraction, which caused work hardening.  Old cannons both brass and iron are notorious for having voids/bubbles in the casting.  Some of the bubbles are quite large.  Most bubbles are in the muzzle end which is where the crown is and where the cannon is poured from.  If you don't have enough molten metal in the crown, then you usually get more bubbles.  The muzzle end is the safest place for the bubbles to be.  Rambling.

James Levy

[Dphariss]

It just struck me reading the post below about the brass barrel, how did they avoid the brittleness that comes from work hardening? Is a brass barrel something you would want anneal periodically?

We had a machine at work that required an automatic brushing to remove char and scale. The steel brush was abrading the tooling so the young pup engineer bought a brass one. It worked well untill the bristles work hardened and became brittle. A young lady operating the machine had a bristle bury itself in the end of her nose about half inch deep.

Brass is not suitable for gun barrels.
The *proper* Bronze alloy is OK based on historical use.
Bronze cannon stood up well over the centuries. Something that cannot be said of cast iron.
I still prefer steel gun barrels and have no interest in copper alloys.

Dan

[LynnC]

Gun bronze will last you a lifetime and several more.  88-10-2 is a  common G-Bronze for cast barrels.  I know guys that will pull the lanyard on their original bronze CW cannons with full sevice rounds.  No Problem......................Lynn

[JCKelly]

There are dozens of "brass" and "bronze" alloys.
Get one that has no lead in it.  Lead makes the Machinist very happy but the barrel not very strong across the grain.
Ampco has several good & more or less available grades.
The best are miserable to machine   Tool wear from the aluminum content contributes, I suppose.
Having said this, bronze is a poor chice for a rifle barrel. Won't dampen vibrations (rings like a bell . . .) so may be less accurate. And for te same size, a bronze barrel is a little over half as stiff as steel. Will "whip" more. Does not rust in the rain but moist powder fouling corrodes it. Keep away from ammonia, horse barns, mice or too much Brasso, can cause those spider cracks with timr. They are real cracks.
Looks real pretty, though. Best kept for pistol barrels in my opinion.
Jim K, RETIRED metalurgist

[Kermit]

I've long been infatuated with bronze--"brass"--gun barrels. It's good to hear from a metalurgist on the subject, however. I'm rethinking my lust...

[hyltoto]

Roger that>>>>

[bob in the woods]

I have had mine for 8 years, and have put 1000's of loads through it.  It is soft, and "sticky" to machine. Riley Smith made it for me, and I think it is a magnesium bronze if I remember correctly.
I really can't say about it "ringing"..this one seems pretty "dead" as far as vibrations go. It is in .50 cal. and is very accurate. It's heavier than the same barrel in steel. 

[Kermit]

Got pics, Bob? I like to watch...

[Brian]

Gun bronze will last you a lifetime and several more.  88-10-2 is a  common G-Bronze for cast barrels.  I know guys that will pull the lanyard on their original bronze CW cannons with full sevice rounds.  No Problem......................Lynn

Lynn - do you have any idea where I could obtain more information about various "gun bronze" alloys?  A bronze barrel is a project I have contemplated for some time, and if I'm going to do it I may as well get the best material I can find.  I'm a little "thick" on some of this stuff, so can you explain 88-10-2 for me?  I assume it is the proportions of various metals in the alloy - but exactly what?  And what else might be as good - or better?

Bob - is there any way you can find out exactly what that alloy you have is?  Thousands of rounds with no problems sounds good to me.

A good thread.  Could not have come at a more appropriate time for me.

[LynnC]

OK - I was once very interested in the study of CW artillery and picked up a little knowledge along the way and have a few good books on the subject of artillery.  The US military spec for bronze alloy tubes (cannon barrels) is as follows:

88 parts copper - 10 parts tin - 2 parts zinc

This exact alloy is also listed in my Machinery Handbooks.
My 1941 ed. spells out Gun Bronze while my early 70's ed. says "G"-Bronze

This may actually be the more "modern" modified G-Bronze with slightly improved casting and machining qualities though I believe this particular alloy dates to the CW.  Prior to this, generally most nations specified G-Bronze to be 90 copper & 10 tin plus or minus a couple of parts. 

Quality full scale CW reproduction gun tubes are currently cast from this alloy.
Talk about some $$$$$!

In the South, Lord only knows what was cast in gun barrels.  From the odd colors some tubes have oxidized to, lead is suspected to be a small but signifigant component.  Bronze tube failures on both sides were almost nonexistant.

Now I am not saying this is the only alloy that a barrel should be made from, only that it has been found traditionally to be a good and safe one.

I would stay away from high zinc alloy brasses as I think they are suseptible to season cracking.  If I remember right, there is mention of this in my Mach. Handbook.  I'm sure there are resourses out there to better educate you (and me)on this subject.  Perhap Jim K could tell us a bit more about what alloys to stay away from and why.  I would like to learn all I can too..................................Lynn

[bob in the woods]

Brian, I will see if I can find out from Riley, what material he used. I will try and post a photo. The barrel is a 7/8ths oct.,  .50 cal.   I'd like to have another one made in a swamped , or oct/round .54 cal

[Jesse168]

Years ago before I came to this site I built a bronze barrel.  I had an old Dixie Gun Works barrel that had been machined off center.  I took it and put it between centers on a lathe and turned the barrel down (made my own rifled barrel liner).  I then took a piece of bronze and drilled and reamed it.  Then I pressed the other barrel into the bronze.  Then I set the barrel up in a milling machine and cut the flats. 

To make sure the inner barrel was secure at the muzzle I left a shoulder at the inside of the muzzle for the liner to shoulder against.  I did make sure the bronze bore at the muzzle was larger than the rifling...sort of a false muzzle.

This is just an Idea for some of yall.

Jesse

[Stophel]

I have an Ed Rayl brass barrel.  Haven't used it yet.  If I remember correctly, he told me it was 70-30 "naval brass" (70% copper, 30% zinc).