The present invention relates to methods and an apparatuses for loading and unloading objects into/from corresponding cavities in holders at a high count rate. For loading, a plurality of objects are present on an object path which mutually converges with a holder path. For unloading, the object path mutually diverges from the holder path. Integration of this method and apparatus respectively into a method of manufacturing unleaky containers and a corresponding apparatus for leak testing containers is also proposed.