Thread: Chamber casts, what material to use?

As per title, what are folk using for making a cast of your chamber?

Sulphur and carbon can be used, it's brittle and shrinks on aging so needs measuring quickly. Cerrosafe, an alloy of bismuth, tin and something elseused in sprinkler triggers is the gold standard

Could you use pewter?

I knew that folk used both but in the past tried to source Cerrosafe in NZ to no avail. If anyone knows where it can be got....

I understand Cerrosafe can be reused over and over also so perhaps a large qty is not required?

I have ready of tinfoil crushed into the chamber and rammed solid makes an acceptable chamber cast.

Havent done it myself so cant confirm the suitability..

https://forum.accurateshooter.com/th...-cast.3883445/

Sulphur and graphite is just fine.
It doesn't shrink enough to throw the numbers out enough to matter

Cerosafe I have used and is good but unobtainable in NZ
Hayes metals sells a product they call cerrosafe in NZ but it is for bending metal pipes without collapse and is not suitable for chamber casting

Good quality garden sulphur from the hardware store is what you want and a puffer bottle of graphite from the key cutting department.
Find a youtube tutorial and see how its done

Be warned when melting it in a pot that it is very flamable so if doing on gas in your workshop that the gas flame can ignite the fumes from melting it.
And that it burns with no visible flame but extremely noxious fumes
And you will struggle to put out the flames if you ignite your surphur graphite mix

So do your research and set yourself up properly and safely
The good thing about the sulphur casts is the product is very cheap so you can keep the casts as a reference long term and label them

You can cast them as a barrel slug and test for tight patches.
Or measure a choke and push back to the breech

Very quick and easy once you have learned from someone else's mistakes

a few other tips

Mildly warm the metal of the chamber you want to cast
Well oiled
Obviously block the bore ahead of the chamber
Big chambers the cast will solidify and the core will hollow out, so keep topping up the center as it starts to cool with liquid mix from your little sulphur pot
Blank off extractor rebates etc with plasacene or blue tack
Have your gun set up chamber up in a vice in SOFT JAWS or well supported vertically

Maybe try this first on a gun that is easy to get at the chamber and not so valuable
I suspect the molten sulphur would damage a wood or plastic stock
I know it will damage you if you get it on yourself
Make sure your pot has a little V pourer lip because it is very hard to get it where you want it when wearing gloves etc

WAIT a decent amount of time to try knocking the cast out.
When casting really big chambers I found that the core wasn't hard even after 5 minutes
So wait until the metal work has cooled to normal ambient temperature before trying to knock it out with the larges cleaning rod you can fit in the bore
And do take your spear point cleaning jag off !

I have casts all over my work benches.
Don't bother trying to re melt and recycle them. They are cheap to make and the solid casts are a lot harder to safely re melt than just using more of the powdered sulphur and graphite

Cerrosafe is accurate for around 1 hour and then changes very gradually over time ... a tiny amount that most of you would never be able to accurately measure.
Sulphur in my experience does not change over time.
But I do record their dimensions and label them immediately after I take them out. I have re measured some and not found that I can find any differences.

All the same can be done to take a chamber cast of reloading sizer dies to diagnose problems

All the above statements are based on my casting single shot rifle and shotgun chambers.

Clearly that is a lot easier than trying to pour molten sulphur through a bolt action into a chamber and getting it where you want it and not over full and partly filling the bolt head rebates.

Also if doing a fixed frame martini chamber don't put your bore plug too far down the bore or you won't be able to get it back out around the corner ( reason number 56 for not liking martini actions )

Well that will teach you for cheating and having those modern fangled repeating rifles !

I'm sure there are many who would be interested in a copy of "One hundred and one reasons for not liking martini actions" by the respected single shot affectianado @akaroa1. Is it currently in print🙂

Originally Posted by Marty Henry

I'm sure there are many who would be interested in a copy of "One hundred and one reasons for not liking martini actions" by the respected single shot affectianado @akaroa1. Is it currently in print��

It is a "living document " and it grew by several new chapters last week when assisting a forum member with a problem martini ( is there any other kind ? ).

There is a companion volume titled " Farquharson yeah nah" "what a shame, it could gave been a fairly good falling block action "

But don't despair all you martini and farquharson owners or aspiring owners I am usually relentlessly possative about vintage single shots

Brownells Australia show Cerrosafe in stock for $67. 55 AUD..However, the only seem to allow Australian customers. Need someone to bring some back. Group buy anyone? I'd be happy to split a bar with someone. Or buy a whole one for that matter.

No one traveling to-from Aus near future?

Happy to post over if that works, pm me.


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