Chamber casting

I believe there's a material known as Cerrosafe, but damned if I've ever seen it handy in the local shop. Pretty sure you can order it online.

Maybe try "Field's Metal" if you know any metallurgical nerds - the stuff melts at VERY low temperatures.

-M
 
The old method is to cast sulphur into the chamber. I did it years ago and it does work. You heat the powered sulphur up until it melts, you then pour it into a lightly oiled and stopped chamber. when cool push it out with a cleaning rod. It's hard and only srinks by about half to one thou. I think the old timers added things like soot and graphite to the mix as well
 
chamber cast

Push a lightly oiled swab about 1" ahead of chamber from the muzzle side.
Mix 75%sulphur (you can find sulphur in garden stores, $10.00) and 25 % Graphite (canadian Tire, auto section, little tubes of graphite powder, $4.00/ea).
Heat to liquid and pour into clean and lightly oiled chamber. Wait 15-20 minutes. Tap out of chamber with a rod inserted from the muzzle side andmake sure cast doesn't fall on the floor cause it will break.
I used plastic funnel and piece of plastic tubing for pouring.
If you heat up the mixture in the house, make sure the wife is away for a week to give you a chance to air the place ! Heated sulphur stinks like wrotten eggs.
Never tried cerrosafe, maybe one day...
Danyboy
 
Cerrosafe works well and can be reused over many times. At the time I bought mine it was only $13/lb. I have also used paraffin wax with good results. With wax I put a cotton string down the chamber like the wick of a candle, in case the wax cracks during removal

cheers mooncoon
 
Cerrosafe works well and can be reused over many times. At the time I bought mine it was only $13/lb. I have also used paraffin wax with good results. With wax I put a cotton string down the chamber like the wick of a candle, in case the wax cracks during removal

cheers mooncoon

X2 for the paraffin wax. Makes a beautiful chamber cast, albeit fairly fragile. Great if you just want to tell the calibre of a rifle, I wouldn't want to send it away to have a die made or anything.
 
Cerrosafe is a Bismuth based alloy that is ideal for chamber casting simply because of its unique expansion/contraction characteristics. Initially on solidifying, it shrinks slightly, allowing it to be easily removed from the chamber of your firearm. After approximately one hour at room temperature, it is exactly chamber dimension, so measuring it after the wait gives you precise dimensions. Melts at very low temp as well, so no danger to fine firearms. Regards, Eagleye.
 
It seems to me that as the Cerrosafe hardens, the dimensions of the cast change with time. Perhaps you are supposed to wait 2 or 3 minutes before measuring, and at some point after that the cast shrinks or expands, I don't recall which. Oops, I see Eagleye nailed it.
 
I've used Cerrosafe, sulphur, sulphur/graphite, and some soft silicone compounds in the past. Each have advantages/disadvantages. Sulphur & sulphur/graphite is cheap & re-usable if you are careful with the heat, but stink and can be pretty fragile. You might also want to avoid getting direct flame too close to the sulphur, especially when in a liquid form. You think it smells bad when melting, try when burning. The silicone casting materials are soft, pricy, and can be so soft that getting exact dimensions with calipers may be a pain. Cerrosafe is in between as far as cost, and works pretty good. Just remember to tap it out soon enough after hardening that it doesn't tighten up on you in the chamber, or it's a pain to get out. It can also be a pain to get out of a severly nicked, bulged or otherwise damaged chamber where the Cerrosafe alloy fills in the damaged area and anchors the cast there. Pouring any casting medium carefully also avoids letting any of it go into places that you'd rather not be stuck cleaning it out of.
 
It seems to me that as the Cerrosafe hardens, the dimensions of the cast change with time .

I think the expansion after cooling is in the range of .001" and probably not worth worrying about in terms of dimensions for making dies to fit and so forth, except for the most fussy of shooters. The principle concern, at least for me, is to knock the cast out soon enough so that it does not get jammed. As mentioned earlier, a pitted, rough or bulged chamber can make things a major bugger to remove but in a real panic, you only have to heat the barrel up to 130 or 140F to melt the cerrosafe out.

cheers mooncoon
 
I've found it at larger well-stocked machine tool supply shops ( i.e. where machinists and tool & die makers buy their specialty "stuff" )

Well don't keep-us in suspense, put their name or address up. It's bad gunsmith etiquette. like putting a Newfie in a round room and telling him to pee in the corner!
 
I once did a Martini-Henry with lead because that was all I had available.
Plugged the barrel just ahead of the chamber with wet paper towel and filled the chamber with wheel weight material.
Waited 10 minutes and punched out a perfect 450/577 cast.

Just ignorant as hell,didnt know any better.:slap:
 
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