Cleaning inside of cases?

Anybody collecting the pre-NATO Cal 30 have probably discovered that the FA 45 cases are very prone to cracking, splitting, and even breaking in two at the shoulder. I’ve lost two of those valuable cartridges so far. I have one that has a split neck and a loose bullet so I am trying to save it. The bullet came out very easy. I dumped the powder and washed the case inside and out with hot soapy water.

So, any suggestions on what I should do next? Should I coat the inside with anything? Should I neutralize the primer? Put the original powder back in? I can duplicate the powder charge with fresh powder of the correct type.


PS - Any ideas on what might be the cause? The powder looks good and fresh. The inside of the case is a dark color. Primer? Brass alloy?


I think that it is due to the brass alloy that with time tends to break up.