I have made lots of cases from 06 brass back in the day and I still make some 8mm Mauser brass now and then but to squeeze down to 7.62X 39 I know it probably could be done but it would be more work than I care to do. As far as carcano brass lots of luck the carcano case and head are considerably smaller than the 06 so the amount of squeezing would be a lot, New brass is available a lot cheaper than it used to be so buy some and save a lot of work.