Chamber Casting?

[Bigjohn]

I know about the materials which can be used for casting a chamber but unfortunately all are difficult to locate in this area.

I have a barrel which I received as part of the estate of a former Bush gunsmith.
The barrel was originally for a No.1 Mk III* .303"; the original chamber has been cut off; the outside of the stub turned down and then soldered into the bored out knox form of a .310" Cadet Rifle. The barrel was then rechambered for a rimmed case somewhere between the .357/.38 rim diam. and the .44 M/Spl rim diam.

There are no other markings to indicate the cartridge and the Chamber reamer was not amongst the rest of his equipment which I received.

So, what can I use to cast the chamber considering the care I may need to take as the barrel is soldered into the Knox form?

Any help would be appreciated.

John

[ARKANSAS PACKRAT]

Bigjohn; In the Dixie Gunworks catalog there was a description of casting a chamber using melted sulphur. As i remember, lightly oil the chamber, plug the bore with a patch and melt the sulphur and pour, let it cool and tap out.
I never tried it, sulphur has really nasty fumes when melted (sulphur dioxide????)
Nick

[Four Fingers of Death]

Brownells have ferro crete or cerro safe I think it is called. Toys for Big Boys in SA handle Brownells products or you can order direct.

[Bigjohn]

Ark. Packrat;
After I posted the thread, I went to bed early and read George Nonte's Book. He had details on the sulphur chamber casting method. I've already checked with my chemist and ordered the sulphur. The rest I should be able to find easily.

Mick,
I can contact "Toys", he tends to be slow with his responses, when I have contacted him in the past. I will try him again but I will have the fallback of the sulphur casting if he can not come through.

I was thinking last night of the possiblity of using hot glue. The barrel is free of any action and access to the chamber is clear. Warm the barrel to 'heavy' status (warm enough to make you put it down, FAST!). Plug the barrel and lightly oil the chamber, slowly squirt in glue, add threaded rod to aid removal.

Prehaps the boys from the R&D of N.A.G.S. can give us their opinion?

Thank you again,
John.

[sundog]

I've got Nonte's book, but I don't recall what he said about chamber casting with sulphur. Maybe I'll look tomorrow.

In the meantime, I will say the I have used sulphur with success. I add graphite and very lightly oil the chamber. It works. My [now deceased] smithy put me on to this, and it works.

I have a small block of cerro safe on the shelf that has never been used. Anyone want to buy it?

[1hole]

I've made several sulphur chamber casts, it works good enough for most uses. I would suggest drying an oiled chamber pretty well before pouring in the molten sulphur. Extra oil may prevent the cast from accurately taking on the chamber's dimensions.

Tips:

For a bore plug, chamber a dummy round and gently push a small wad of tissue large enough to make a full seal through the bore until it seats firmly on the bullet tip. That will allow your cast to show a small part of the chamber's leade and rifling too.

Don't bother to mix in other stuff, the "flowers of sulphur" powder works well enough alone.

Don't over heat the sulphur powder, excess heat makes it congeal into a thick mass that can't be poured very well. If that happens, just toss it out and melt another batch.

Use a small heat source and pot. I use a large candle and an old aluminum 35mm film can with a wire handle for a pot.

Make yourself a half inch by eight inch long, tapered-cone funnel from a sheet of paper to guide the pour through the action, hold it in place with tape.

Don't over fill the chamber! Doing so makes it hard to remove the cast without breaking it and the excess sulphur is hard to completly remove from the locking lug recesses.

Handle the finished cast gently, it is brittle and easy to break. I store my old casts in short sections of half-inch CPVC plastic pipe.

Have a small bucket of water handy when melting the sulpher. It can be used to put out a fire AND is very good to dunk your hand or fingers in if the melted "brimstone" gets on your skin.

[uscra112]

I get my "Cerro" alloys from a large industrial supply house here in the USA. McMaster-Carr. www.mcmaster.com They sell on the web, and may ship internationally. Credit card, no minimum. A REAL useful source. If they don't have it, you don't need it.

There's various types of "Cerro" alloys, used for making one-shot forming dies, bending thin-wall metal tubing, and also for fixturing odd-shaped parts for machining.

The maker of all the "Cerro" alloys is Cerro Metal Products Company.

Other names for it are "Wood's metal", and "pewtalloy". The "Cerro" names are all trademarks.

Look up the mill supply companies in Oz, and you will find a source.

[Bigjohn]

The Home Guide to Cartridge Conversions by George C. NONTE Jr.

Chapter 3; Calibre Determination Page 18.

4 ounces of Sulphur
a pinch or two of Lamp Black
teaspoon full of Camphor dissolved in alcohol

Melt this mixture ever so slowly over a low heat while stirring constantly. When it reaches the consistency of thin cream, it is ready to pour.

The details of bore preparation have been mentioned in this thread previously.

John