Gunsmiths: chamber cast advice?

Make sure your barrel plug in front of the chamber is really tight. A little grease can help fill in all the lands and grooves.



Iraqveteran8888 has a few too. They are longer and more detailed.

A good hardware store will have a supply of corks in a variety of sizes. A greased cork will fill the bore well and withstand the molding process.

Assuming that you are using Wood's metal (cerrosafe) or something like that, corks or rubber testtube type corks work with a hi temp grease. The other thing is cerrosafe must be removed during its contraction phase within 30 minutes after pour and measured at one hour as that is when it is more or less exact measurement of chamber. It continues to expand slightly so that after 200 hrs it is .0025" larger than your chamber in dimensions. I've only read about using sulfur and it would be a pain to deal with so no recommendations there.

This is Sinclair International's (a Brownell company) instructions
https://www.sinclairintl.com/guntech/casting-your-chamber-using-cerrosafe/detail.htm?lid=16061

Before the Internet I started casting chambers, my methods and or techniques are too antiquated to help the 'modern reloader' and then there is the other problem; there is a very good chance someone will see and or read about something they never saw before. And then the post gets deleted.

F. Guffey

delete

Before the Internet I started casting chambers, my methods and or techniques are too antiquated to help the 'modern reloader' and then there is the other problem; there is a very good chance someone will see and or read about something they have never seen and or read nefore . And then the post gets deleted.

F. Guffey

fguffey I used to use sulpher for chamber casting before cerrosafe. Is that what you're talking about?

fguffey I used to use sulpher for chamber casting before cerrosafe. Is that what you're talking about?

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No, forgive, my methods and or techniques are so different most reloaders on reloading forums have trouble dealing with the author or methods. reloaders seem to be very comfortable with the MidwayUSA and Sinclair methods or they are resistant to change. It is easier on me if I do not provoke them to think.

F. Guffey

fguffey said:

No, forgive, my methods and or techniques are so different most reloaders on reloading forums have trouble dealing with the author or methods. reloaders seem to be very comfortable with the MidwayUSA and Sinclair methods or they are resistant to change. It is easier on me if I do not provoke them to think.

F. Guffey

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Ok, curiosity killed the cat here. PM me how else you'd do a chamber cast if you don't want to stir the nervous Nellies up. I'm truly intrigued.

Hopefully it will be something to the tune of committing the dastardly crime of using a tap to chase threads instead of a dedicated thread chaser.

earlthegoat2 said:

Hopefully it will be something to the tune of committing the dastardly crime of using a tap to chase threads instead of a dedicated thread chaser.

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There’s a difference!!!!! Oh no!!!!!!!!

boom boom said:

Assuming that you are using Wood's metal (cerrosafe) or something like that, corks or rubber testtube type corks work with a hi temp grease. The other thing is cerrosafe must be removed during its contraction phase within 30 minutes after pour and measured at one hour as that is when it is more or less exact measurement of chamber. It continues to expand slightly so that after 200 hrs it is .0025" larger than your chamber in dimensions. I've only read about using sulfur and it would be a pain to deal with so no recommendations there.

This is Sinclair International's (a Brownell company) instructions
https://www.sinclairintl.com/guntech/casting-your-chamber-using-cerrosafe/detail.htm?lid=16061

Click to expand...

You mention a very, very important aspect concerning the use of "Cerrosafe". It's the exact reason why I shy away from it these days. When I was involved working with a company where we manufactured military procurement parts that we reverse engineered due to the fact that prints were no longer available, I used a product called "Facsimile" to measure internal parts to gain an exact reproduction of those dimensions. Worked very well, and I now use it for older .22 rimfire rifles, especially some of the Stevens rifles that have odd-ball threaded screws that can only be replicated on a lathe. This stuff saved my bacon many times.