Casting an all brass firearm

[cdg]

I am posting this out of curiosity after seeing a couple of brass derringer kits on the internet, and finding some historical brass firearms. It appears as if such firearms are made completely of brass (save for grips and locks). See this interesting pocket pistol:

http://www.antiqueguns.co.nz/Pm264.jpg

or the following derringer kit offered today:
[url] http://www.dixiegunworks.com/product_info.php?cPath=22_162_194&products_id=3440[/url]

I am curious about how brass is cast and/or treated for use in a firearm. Are there special methods employed to help stregnthen the brass? I know that brass can be cold forged, but this would also make the metal suceptable to cracking. However if it were left too maleable, it would be suceptable to stretching if fired much.

Obviously brass is strong enough to handle substantial pressures- case and point the old "napoleons" of our Civil War.

Now it all comes out- Brass melts at low enough temperatures to make it possible to cast brass more or less easily in an electric kiln. Is it possible to produce your own barrels or frames? Obviously additional machining work would still need to be done, and I don't know enough about that sort of thing to really consider such a project for myself.

However, suppose I was interested in something where safety is less critical, like something to fire blanks or wads of newspaper? Maybe a crude matchlock cannon to make noise with? How can you calculate the "load" to be used for a blank. Am I just asking to blow myself up? :haha:

Well, your thoughts are appreciated. I'm mostly just curious about how it is done for brass firearms. I understand that many steel firearms employ forged barrels and varying methods for constructing frames. I don't know why, but I've always had a facination with brass firearms.

 

[BlackNet]

brass is the opposite of steel for tempering. You heat it up and quench it in water (or let it air cool) to make it softer. To harden brass (and copper) you hammer it and work it.

Casting is done in an interesting way. If you ever been in a foundry it's a very pleasure to watch how it's done. They liquify the metal, take sand and mix it with stuff and form 'green sand' then take styrofoam and make a template and press the sand around it, the compression makes the sand hard and forms a very good bond. remove the foam and pour the liquid metal into the recess.

When it's all nice and cool the object comes out of the sand and to the machine shop for processing. all the shavings are then recycled back to the melt deck where it starts all over again.

When mixing metals you have a ratio of all the parts to make up the whole, say brass and zinc, or copper or silica, etc.. they will take core samples as it's being mixed to a machine which sends an electric arc thru the sample then connect info and print out the % of all the elements in there. The results goes to the melt deck which adds products to the mix to make the ratios fall in place.

Wax casting and sand casting is done in the same manner, both will yield the same type results but the real kicker is how it's mixed and melted. that's the real secret behind any type of casting.

Post melt deck treatment is done in the machine shop and there it's cleaned up and checked for errors, rejects are recycled and those that pass are then sent to be refined further.

By over processing, i.e. hammering, brass and co it will make it very brittle. If you look at some of the kits like the queen anne kit the remarks people make is the trigger guard is to fragile and they tend to break easy. Good signs of over worked metal

hope this helps.

Ed

 

[WRussell]

I remember reading about a gunmaker in the late 1600s? Early 1700s? Trying to make a name for himself with brass barrels. He had worked out a technique for cold forging them down to thin and light, making them stronger at the same time. Nothing came of it. It would only take a couple of exploding barrels to make his name mud.

 

[WRussell]

Oh, and a lot of old "brass" guns are really bronze. Way too many alloys involved.

I agree, brass is nice. Bronze bearing stock is available in the form of heavy wall tube - perfect for making a bronze barrel.

 

[cdg]

Hey, thanks for the great info! I have indeed been to a foundry before- fairly recently to a place that sand casts bells. Really neat to see some of those guys work, and the speed at which they can work.

I have also seen wax casting done in a kiln before- where the wax form is made, plaster placed around it, mold heated until wax melts out of form, and finally metal poured into the form. I've only seen that done with silver though. I think the fellow told me the same thing could be done with brass as well though...

 

[cdg]

I took a metals class in High school where I learned to sliver solder and make some jewelry. We had brass, bronze, copper and silver (you had to pay for silver) at our disposal. I guess it was my second piece, and my first design that was a candleholder made of thick brass wire twisted around. It looked pretty decent all in all. Anyway I guess my point was that the ends of the "feet" of the holder were hammered down and curled up. In short, my first attempt I learned the line between hardened and brittle!

I can see how a manufacturer that made thin brass barrels might have failed- it's really tough to tell exactly when you've overdone it with brass...

 

H

I have also seen wax casting done in a kiln before- where the wax form is made, plaster placed around it, mold heated until wax melts out of form, and finally metal poured into the form. I've only seen that done with silver though. I think the fellow told me the same thing could be done with brass as well though...

It's called 'ceres perdue' or lost wax casting. It is used to make precision castings; Ruger uses it to make their firearms.

 

[BlackNet]

also note this is where 'proof marks' originated from. Guns would fly out of the plant untested and unfired only to blow up or be fired a few times at best. The british crown enacted all guns go thru a proof mark process meaning the manufacture put their stamp on indicating it was fired before leaving.

Ed

 

[dlemaster]

CDG
If you get a copy of Rifles of Colonial America Vol.2 By Shumway (available thru inter-library loan) there are a number of pictures of the famous "Brass Barreled Gun" in it that you would find interesting.

Regards, Dave