This invention discloses an apparatus and method for receiving small containers and articles in a determined array and from a single side accumulating and feeding these containers or articles in a series of loading moves into the end of an erected carton. In the embodiments shown, provision is made for a carton size change within determined limits. These case packing apparatus assemblies shown are for packing small containers such as quart or pint paint containers and in an alternate arrangement for packing a multiplicity of sponges. Automatically actuated fingers that engage the lower extent or surface of folded cartons and then move into slots to engage upper flaps or carton extents are also shown.