I read whats in the Brownells catolog about cerresafe. Seems straight foward.

Are there any tips you guys have for doing a chamber cast?

pretty well covers it. Do remove it before the hour. Years ago I left and went and ate dinner. Got to redo it after I melted it out of the chamber. Unless this is a learning experience since you are going to send your rifle to be rechambered let them do it.

First, make sure you melt all of the cerrosafe bar. Melting just a part of the bar can cause a problem because the bar is not homogenized. Having said that, clean your chamber normally, and push a plug of cloth, usually cotton, ahead of the chamber and slightly into the rifling so you get a casting of the chamber, throat, and beginning of the rifling. This will show you how everything looks in relation to everything else.

It is best to position the rifle with the muzzle down, and securely fastened. Warm the chamber of the rifle and a short section of the barrel with a hair dryer for a few minutes until it is almost too hot to hold. Pour the melted cerrosafe slowly as not to cause air bubbles, and pour in enough to extend a little past where the back of the shell would come to if the rifle were loaded.

Let everything cool for 10 minutes or so, and then tap out the casting with a cleaning rod from the muzzle. It should take only one or two whacks with the palm of your hand.

If the casting is frosty, the metal was too hot when it was poured. If it has wrinkles or bubbles, the metal was too cold and the gun barrel and chamber should have been warmer.

If you don't like the cast you just got, make another. It only takes a few minutes, and tells you so much. Take your time, and you will find it easy. Good luck.

What that cerrosafe material like? kind of like lead? Aluminum? A metal? Wax? Or what?

Its a bismuth and tin alloy.
one other note, its really easy to over heat and ruin the alloy if you melt it with a torch. Use a small can and melt it on the stove.

It is an alloy, main ingrediant is Bismuth, I think. I guess you could say that it looks like molten lead when in the liquid state.
There are alloys that melt at a lot lower temps than "Cerrosafe" but they get expensive.
Sometimes called "woods metal".

How low a temp. do you want it to melt at? Cerrosafe melts in boiling water.

The danger is the cadmium, that is also in the alloy, is driven off at high temp. If IIRC the cerro pots we used didn't get over 250-280F max.
A double boiler would be perfect.

I melt it in a coffee cup in a couple of inches of boiling water on the stove. Just about the right temp.

quote:

Originally posted by Rusty Marlin:
Its a bismuth and tin alloy.
one other note, its really easy to over heat and ruin the alloy if you melt it with a torch. Use a small can and melt it on the stove.

I don't know how many years I've been using this same chunk of cerrosafe, but I use an old tuna can and propane torch to melt the stuff... Sometimes I get it pretty hot. It's still working great!

Glad I save my Tuna cans.

This is off topic on the chamber cast but I've got to share it anyway (sorry for the thread highjack GSP7). A friend brought over an old octagon barreled Ballard 22 rifle that he wants to have a liner installed. I couldn't get the barrel loose with my usual methods. We set the barrel up vertically in a vice, placed a pair of barrel vise bushings around it, space the two bushing halves apart with modelers clay with some more clay around the bottom to control the mess, then fill the space between the barrel and the bushing with cerrosafe. That "custom made" octagon barrel bushing worked perfectly in my barrel vise.

I use an aluminum soda can cut in half, heated double-boiler style.

Three tips:

1. Cut the can so there is a long "spout", then bend the spout into a "v". This makes it easier to pour into the small area without spilling it all over.

2. Have your chamber close to where you are doing your heating. Pour as soon as you can after removing from heat.

3. If you can't see down the "hole", have a good light shining down to help you judge when you have a complete pour.

Other than that, just follow the included instructions.