Making a Chamber cast?

[325Cpl]

Hello everyone,I have a question I hope you can help me with. I just aquired a Argentine Rolling Block and from what I have read on here,it is advisable to make a chamber cast first to make sure it has not been rechambered at some point.My question is,how do you do this.I have read the product information about Cerrosafe on the Brownells website but would like more details,like do you pour it all the wat to the top so the rim is part of the casting? Any help is appreaciated.

[marlinman93]

Just one other thing to add. Let it cool and it will come out easier than if you try to get it out quickly. A quick rap on a cleaning rod will free it up.

[325Cpl]

Thanks for the pics. I finally got around to ordering some cerrosafe and as soon as it gets here I will give it a go!