If you want to use future subjunctive here (recall it's not used in anything but the most formal of documents), then the pattern is Si fut. subj., fut. ind.. In your example
Si él charlare conmigo de nuevo, seré distante.
That usage is pretty much entirely extinct in Spanish, though it is preserved in Portuguese: Se ele conversar comigo de novo, serei distante
Future subjunctive, in the rare case that it's used in Modern Spanish, tends to be limited to relative clauses where it can be contrasted with present subject:
- Seré distante hacia el que me intentare conversar
(… to whomever tries to converse with me; it's possible that no one will try)
- Seré distante hacia el que me intente conversar
(… to whomever tries to converse with me; someone will try, I just don't know who)