lol Well push comes to shove, remove barrel pin, pull barrel, insert it into a lathe, dial in concentricity, mark proper length, insert threading tool, select proper settings (Speeds and feeds baby.), turn it. Check threads with thread gauge, remove from lathe, repress barrel, insert barrel pin.
There is always a way when you have enough material.
But most just wanna use a die. It's understandable. Don't forget your Tap Magic and to make sure your threads are concentric to the center of the bore before you start tapping.