I have a 1:1 clone and both attys. Zero issues getting flush without rattle.
Bear in mind there are 4 pieces which screw together in the top cap:
Copper Top Cap > Black Insulator > Large Copper 510 Pin > Small flat head adjustment screw
The small screw was very stiff on mine and required a lot of work to get moving and smooth. Take the top cap apart and gently use pliers to separate all these 4 pieces, then clean and spray with silicon contact cleaner.
When reassembling, snug up the black insulator first, then screw the atty down tight. Then screw in the large 510 screw until tight with atty. Finally screw in the smaller flat head screw and adjust for battery rattle.