One aspect of the present disclosure relates to devices for sealing gaps in an extrusion assembly to provide for a consistent extrusion. In one embodiment, a barrel-shaped sealing device with a resilient protruding edge is used to prevent extrusion material from entering gaps between the piston and the inner surface of the barrel. The sealing device includes a fastener to releasably attach the sealing device to the piston. Sealing rings are inserted into a bottom gap formed between the bottom edge of the barrel and the bottom surface of the die.