Importing unsupported Bugzilla custom fields into JIRA
Introduction
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.
A feature request to make this feature native in the Bugzilla Importer in JIRA can be found here:
Known Problems
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)