Packaging machine and method for filling open-mouth bags comprising a filling spout, wherein by way of a motion oriented upwardly relative to the filling spout an open-mouth bag can be appended to the filling spout. A dosing device and a weighing device are provided for weighing a pre-defined quantity of a product intended for bagging. A volume flow control device is provided to control during the filling process a strength of the volume flow into the open-mouth bag in dependence on the time. The volume flow control device comprises a filling element and a control device to control during the filling process a strength of the volume flow into the open-mouth bag in dependence on the filling process so as to keep the top bag wall of the open-mouth bag substantially free of product intended for bagging. The filling element serves as a dosing device to transport the product intended for bagging from a dispensing silo into the open-mouth bag. The weighing device is configured as a gross-weighing device to determine during the filling process a measure for the weight filled into the open-mouth bag. A compactor is operated during the filling process.