[Cat Whisperer]

I have a few concerns about how discussions have been going.

We've certainly run through a range of emotions today.

First and formost is my concern for safety, then legality, fun and politeness.

Let's keep the remarks civil - if you don't agree, say so, AND explain your
concerns and reasons (in enough detail to be of some educational use).
Comments like 'go open a book and find out' are unwarrented. As some have observed, the strength of this forum is the free and open flow of ideas and wide ranging discussion - lets keep that tradition.

So where will this topic go? Hopefully in a detailed discussion of the type of strengths and characteristics of materials suitable (or not) for making barrels.

Again, the issue of safety is foremost. When it comes to design, most of us are neither metalurgists nor mechanical engineers by training or trade.

So the best alternative is to observe what others have done successfully over a period of time - and add a significant safety factor in our copy.


So, to start with, allow me to say that modern rifle barrels are often (perhpaps most often?) made of 4130 or 4140. Hence because of the high pressure applications, should be a good candidate for barrels we play with.

 

[Cat Whisperer]

Here are a few steels of interest - of note are the types of applications listed in the text.

12L14 (a resulpherized steel as is 1144sp )
http://www.geocities.com/SiliconValley/Campus/8262/htdocs/steels/12L14.html

4140 (used in barrels)
http://www.geocities.com/SiliconValley/Campus/8262/htdocs/steels/4140.html


1018 (offen referred to as cold-rolled, but can also be hot rolled.)
http://www.geocities.com/SiliconValley/Campus/8262/htdocs/steels/1018.html


8620 (used in M-16 bolts - tough stuff!)
http://www.geocities.com/SiliconValley/Campus/8262/htdocs/steels/8620.html

 

[claypipe]

[argumentative/inflammatory remark(s) deleted by CW]

So, to start with, allow me to say that modern rifle barrels are often (perhpaps most often?) made of 4130 or 4140. Hence because of the high pressure applications, should be a good candidate for barrels we play with.

These will definitely do the job, but will add to production time and cost of material and tooling. Green Mountain uses 4140 for their Sharps BPCR barrels.

 

[guardsgunner]

CW,
You might want to talk to a metallurgist before deciding on 12L14 as a steel for an serious Artillery project. MHO and not based on any claimed knowledge of anything at all.

 

[HotGuns]

I do have a concern about the what the references have to say about some of the steels such as 12L14.


Due to high sulfur content, these grades are not considered as weldable.

Weldable? we do it every day at work with no problems. It may not be the best or easiest to weld but it is weldable.

Hardening

Although these grades will respond to conventional treatments, they are not considered case-hardening steels. Better results can be obtained from 1117 or 1018.

Conventional treatments ? It dosent have enough carbon in it to be heatreated by anything other than case hardening. Many rifle and pistol dies are used with case hardened 12L14. I've case hardened many tools made from it over the years with good success.

 

[Cat Whisperer]

I do have a concern about the what the references have to say about some of the steels such as 12L14.


Due to high sulfur content, these grades are not considered as weldable.

Weldable? we do it every day at work with no problems. It may not be the best or easiest to weld but it is weldable.

Hardening

Although these grades will respond to conventional treatments, they are not considered case-hardening steels. Better results can be obtained from 1117 or 1018.

Conventional treatments ? It dosent have enough carbon in it to be heatreated by anything other than case hardening. Many rifle and pistol dies are used with case hardened 12L14. I've case hardened many tools made from it over the years with good success.

I think the issue of weldability is to reduce some folks expectations of it being easily weldable. I usually will look at 3 or 4 references to see what perspectives are portrayed. If there's a concern that's valid it will show up in most all of the refereneces.

I look at case hardening and nitriding as conventional treatments when there isn't enough carbon.

Again, I appreciate your comments - the voice of experience doesn't have to talk very loudly for me to listen.

 

[Cat Whisperer]

CW,
You might want to talk to a metallurgist before deciding on 12L14 as a steel for an serious Artillery project. MHO and not based on any claimed knowledge of anything at all.

If you look at Hotgun's post on the comparison of 1144sp and 12L14 there are some very good points made.

There is a drawback on 1144 being of crystaline structure - IF the elastic limit is exceded or IF the interior ballistics do cause some damage to the interior of the bore. This is the point where experience comes in - taking a look at what has been successful in others' practice.

But in perspective, any of our modernday materials is much more uniform in manufacture and of much greater strength, ductility and toughness than the originals made only 100 years ago - and we're looking at designs of 2-300 years ago (OK, black powder is better too.)

There are rules of thumb of design - from experience. Claypipe has one on miniimum barrel thickness. The N-SSA has one on miniimum breech thickness - and is one that I respect because of it's very broad and successful application over a long number of years.

 

[dominick]

Dillsburg Aeroplane Works, Dillsburg PA. ph# 717- 432-4589 is one of the largest suppliers of 4130 condition N tubing and stock on the east coast. More than half of their business is selling materials to the gun making industry. They carry heavy wall 4130 tubing that would be ideal for a small caliber handgonne. I also have been using the same rule of thumb as Claypipe when it comes to breech thickness (wall thickness = bore divided by two) or (bore x two = breech O.D.) I only apply this rule when using 4130 and have built and fired many cannons without mishap using the proper powder load.

 

[Cat Whisperer]

Dillsburg Aeroplane Works, Dillsburg PA. ph# 717- 432-4589 is one of the largest suppliers of 4130 condition N tubing and stock on the east coast. More than half of their business is selling materials to the gun making industry. They carry heavy wall 4130 tubing that would be ideal for a small caliber handgonne. I also have been using the same rule of thumb as Claypipe when it comes to breech thickness (wall thickness = bore divided by two) or (bore x two = breech O.D.) I only apply this rule when using 4130 and have built and fired many cannons without mishap using the proper powder load.

I have a lot of respect for suppliers of aircraft materials - for obvious reasons.

Key words - good to hear them expressed again - "using the proper powder load".

Thanks for the source!

 

[claypipe]

Dillsburg Aeroplane Works, Dillsburg PA. ph# 717- 432-4589 is one of the largest suppliers of 4130 condition N tubing and stock on the east coast. More than half of their business is selling materials to the gun making industry. They carry heavy wall 4130 tubing that would be ideal for a small caliber handgonne. I also have been using the same rule of thumb as Claypipe when it comes to breech thickness (wall thickness = bore divided by two) or (bore x two = breech O.D.) I only apply this rule when using 4130 and have built and fired many cannons without mishap using the proper powder load.

[argumentative/inflammatory remark(s) deleted by CW] On calibers .69 to 1.0 I would use a dual chamber, the smaller chamber being a diameter of .500 to .562. And I shouild mention I am not a propoent to welding on gun barrels of any kind.

 

[Cat Whisperer]

... Okay, when did we switch from handgonnes to artillery? ...

And I shouild mention I am not a propoent to welding on gun barrels of any kind.

It's not uncommon for there to be more than one topic in a thread around here.

AND, although it CAN be done if done correctly, I agree with not welding barrels. I have done it, but the risk of cracks makes it worth the effort (to me) to go another route. On the flip side, I know some certified welders and folks that do the certification - their welding I trust.

 

[guardsgunner]

Claypipe
Blackpowder mortar and cannons is the titled topic for this board. Artillery.
Handgonnes are kind of off topic but the discussion of this thread. Ok fine by me. I'm into anything that shoots.
12L14 was being recommended as a material to be used in construction on this board. So I express my concern for its use by those of this board.
12l14 is the stuff they make the cheap screws you buy at the local hardware store out of . You know the kind where the head strips at the first use. The 12L14 machines like a dream (The lead helps here) and looks good on paper; it was recommended to me not to use this material as it COULD fracture after having been drawn (such as to octagon)and put under peek pressure's.
I am not a metallurgist but would check with one before using 12l14 for an artillery project.

safety Was my only thought. There were at least 2 accidents last year with people and there homemade cannons which did not have happy endings. They got national news coverage. Cannon shooting events do not. Everytime something goes wrong makes it one step closer to not being able to do it at all.

 

[Third_Rail]

[argumentative/inflammatory remark(s) deleted by CW]... I thought that claypipe said he was a metallurgist.


So I guess I'll tough it through 4140 or 4130, then heat treat. Easy machining isn't anywhere as important as safety.

 

[GGaskill]

You won't need to heat treat. The annealed state is strong enough and it is more malleable (less brittle) that way.

 

[claypipe]

Claypipe
Blackpowder mortar and cannons is the titled topic for this board. Artillery.
Handgonnes are kind of off topic but the discussion of this thread. Ok fine by me. I'm into anything that shoots.
12L14 was being recommended as a material to be used in construction on this board. So I express my concern for its use by those of this board.
12l14 is the stuff they make the cheap screws you buy at the local hardware store out of . You know the kind where the head strips at the first use. The 12L14 machines like a dream (The lead helps here) and looks good on paper; it was recommended to me not to use this material as it COULD fracture after having been drawn (such as to octagon)and put under peek pressure's.

Okay, let's sort this out. I was on the subject of materials used for the making of handgonne barrels. And I will stand by what I have said in the use of 12L14 steel for gonne barrels. 12L14 has been used for years without problems by custom muzzle loading rifle barrel makers such as Colerain and Getz. And those are swamped octagon barrels. If its good enough for the best in the business, its good enough for me.

I am not a metallurgist but would check with one before using 12l14 for an artillery project.

safety Was my only thought. There were at least 2 accidents last year with people and there homemade cannons which did not have happy endings. They got national news coverage. Cannon shooting events do not. Everytime something goes wrong makes it one step closer to not being able to do it at all.

Safety is the only reason I said anything in the first place. After 30 odd years of firearm repairs and refinishing, you learn a thing or two. And its not just cannoneering. For instance the two people that were injured following an age old custom of chasing away evil spirits using family muzzle loading heirlooms and overcharged blanks. It effects us all, whether we like it or not.

 

[claypipe]

WTF... I thought that claypipe said he was a metallurgist.

So I guess I'll tough it through 4140 or 4130, then heat treat. Easy machining isn't anywhere as important as safety.

At no point did I state I was a metallurgist.

I did, however, say that one should know their metalurgy when making gonnes barrels.

Over the years, working on vintage and antique firearms and later gonnes, I studied upon what metals best to use for my repairs and gonne barrels. Don't like the idea of using 12L14, then try 1137, that's what Green Mountain is using for their BP muzzle loading rifle barrels these days.

Remember, the harder the steel, the more fragile it becomes. Over do a casehardening and it will shatter just like glass. Gun, cannon and gonne barrels all need to stretch a bit when breathing fire.

 

[Third_Rail]

My mistake, I thought you had stated you were a metallurgist.


4140 is what I'll be using for my projects from now on re: firearms. Cost be damned, time be damned, safety is paramount.

 

[Cat Whisperer]

.... 4140 is what I'll be using for my projects from now on re: firearms. Cost be damned, time be damned, safety is paramount.

Certainly not a bad choice. I've made a couple of dozen mortars of 4140 just to ensure they were overbuilt. Cost - minor. What's a few bucks compared to the overall cost of manufacture (time and money) and considering the cost of failure.

 

[Third_Rail]

Agreed on that. Did you bother with heat treating?

I doubt I will - just overbuild them further.... breech thickness = bore diameter, barrel thickness = 1/2 bore diameter. Out of 4140, and with reasonable loads of powder, that'll be plenty strong. Now just to get about 10 million opinions, to make sure!

 

[charcoal]

Hello,long time lurker.I have been following the materials choice dilema.Have looked at old threads on designs and construction,very nice projects!!I am going to list what current smokeless and BP barrel makers are using.I agree with the attitude to "overbuild",use sane powder charges.Hope this small addition helps in the material selection process.Also look to Oehler research for pressure testing equipment.


http://www.riflebarrels.com/products/default.htm
http://www.hartbarrels.com/
http://www.rifle-barrels.com/
http://www.gmriflebarrel.com/
http://www.badgerbarrelsinc.com/
http://www.montanarifleman.com/barrels.htm
http://www.barsto.com/
http://www.schuemann.com/ (check out the barrel steel listing)
http://www.obermeyerbarrels.com/steel.html

Pressure testing equipment:
http://www.oehler-research.com/