Importing unsupported Bugzilla custom fields into JIRA
There are certain built-in custom fields from Bugzilla that cannot be imported directly into JIRA using the Bugzilla Importer wizard, such as the QA Contact field.
One method to circumvent this is to export the field information from Bugzilla's database into a CSV-format file, and use the CSV Importer in JIRA to import them.
Note that by using the CSV Importer, an issue's Date Modified field will be overwritten with the date the CSV import was performed. There is no workaround to prevent this from happening. (One way to fix this is to manually update JIRA's jiraissue table. Remember to take a database backup first)