I'd use a drum whose thread journal was the same size as the width of the flat into which it screws, and use a fine thread. 1/4" is definitely not it.
I'd use a blank drum too. Be sure that the threads are cut to the shoulder of the drum, and countersink the barrel just enough. Run the drum in until it is firm without stretching the journal. Then drill and tap for the nipple. A large drum barrel will give you full nipple thread depth...