In meantime I get some further informations.
It looks like that my gatling pawn blueprint that is added in my player_character don´t get any inputs because my player_character is possessed the gatling needs to be possessed to get any inputs and this isn´t the way it should work.
I really wondering, is it really impossible to give 2 blueprints(player_character and pawn) an input action at the same time ?
I can´t programming all this diffrent weapons in the payer_charakter or controller, I just want to have the ligic into the weapon blueprint.
Is there any way to get this working ?