Cerrosafe
- Thread starter Contender
- Start date
Hi Contender - I held off posting on this in hopes that someone with a lot more experience than I would answer your question. But they haven't, so here goes.
I used Cerrosafe to get the chamber and throat dimensions of a Rem. 700 I have in .270 Win. To be honest it was a disaster, I'm still trying to get it out of the head area of the chamber. There must be a good method to pouring it in and being able to extract it with the Cerrosafe "slug" intact. But I can guarantee that I didn't use that method if it indeed exists. I followed the instructions explicitly (right temp., wait the prescribed time, etc., etc.) but without any real success.
So I guess my advice would be to have someone who has had success with it to show you how to do it the first time - I wish I had. Or get an experienced gunsmith to pour it and create the slug for you.
I used Cerrosafe to get the chamber and throat dimensions of a Rem. 700 I have in .270 Win. To be honest it was a disaster, I'm still trying to get it out of the head area of the chamber. There must be a good method to pouring it in and being able to extract it with the Cerrosafe "slug" intact. But I can guarantee that I didn't use that method if it indeed exists. I followed the instructions explicitly (right temp., wait the prescribed time, etc., etc.) but without any real success.
So I guess my advice would be to have someone who has had success with it to show you how to do it the first time - I wish I had. Or get an experienced gunsmith to pour it and create the slug for you.
Contender,
I have used Cerrosafe and can verify that it was a learning experience.
The biggest trick I learned to help the quality and accuracy of the casting is to pre-heat the area of interest (the chamber area). I used a propane torch, and the blueing wasn't damaged. The thermal shock of molten Cerrosafe contacting a cool chamber causes a frosty appearance, much like a cold solder joint. In this circumstance the dimensions change a lot during the cool down period. Preheating helps minimize that.
In my case, a .25-'06 chamber, that was bad about throwing extreme flyers unless I necksized and indexed at the shell holder and at chambering
, was shown to have a classic case of throat erosion, from the mouth of the case right on up into the rifling. ...
Argh!
The instructions with the ingot explain the changing dimensions of the casting as cooling and seasoning occurs. Believe it.
- sensop
I have used Cerrosafe and can verify that it was a learning experience.
The biggest trick I learned to help the quality and accuracy of the casting is to pre-heat the area of interest (the chamber area). I used a propane torch, and the blueing wasn't damaged. The thermal shock of molten Cerrosafe contacting a cool chamber causes a frosty appearance, much like a cold solder joint. In this circumstance the dimensions change a lot during the cool down period. Preheating helps minimize that.
In my case, a .25-'06 chamber, that was bad about throwing extreme flyers unless I necksized and indexed at the shell holder and at chambering
, was shown to have a classic case of throat erosion, from the mouth of the case right on up into the rifling. ... Argh!The instructions with the ingot explain the changing dimensions of the casting as cooling and seasoning occurs. Believe it.
- sensop
The Dec 2000/Jan 2001 issue of Machinist's Workshop magazine has an article by Mr. Steve Acker titled "Making a Chamber Casting". He describes the complete process for using cerrosafe alloy. The mag is available from Villege Press, 2779 Areo Park Drive, PO Box 629, Traverse City, MI 49685. Phone (800)447-7367. The cover price is $4.50US.
As the material is copyrighted, I will not attempt to render it all here. But the salient points seem to be:
1. Cerrosafe alloy 158-190 degs F
2. Better to have barrel removed.
3. Barrel should be clean & between 70-100 degrees.
4. He gets good results by spraying WD-40 in barrel & removing excess with compressed air.
5. Plug barrel about 2" in front of the neck with clean cotton patch.
6. If possible, pour through a long necked funnel, so the pour begins as far into the chamber as possible.
7. Remove the casting as soon as it solidifies.
8. Wait 1 hour before making measurments.
Enjoy
John R.
Seneca, MD
As the material is copyrighted, I will not attempt to render it all here. But the salient points seem to be:
1. Cerrosafe alloy 158-190 degs F
2. Better to have barrel removed.
3. Barrel should be clean & between 70-100 degrees.
4. He gets good results by spraying WD-40 in barrel & removing excess with compressed air.
5. Plug barrel about 2" in front of the neck with clean cotton patch.
6. If possible, pour through a long necked funnel, so the pour begins as far into the chamber as possible.
7. Remove the casting as soon as it solidifies.
8. Wait 1 hour before making measurments.
Enjoy
John R.
Seneca, MD
Got that issue. Home Shop Machinist & Machinist Workshop are both excellent pubs for the more serious hobbyist. Steve Aker has a series of videos out, some sold thru Brownells, that are excellent instruction on building rifles. They are a bit dry, definitely expensive, full of good info. Worth every penny for the serious gun crank.