To make the body of the clay  extruded gun , I used an empty Silicon tube ,carefully cut off the end see image.  Fig 1a

Let the residue of the silicon left inside dry out, then carefully push out the sliding plunger, then  remove the excess dried silicon residue by peeling it out of the tube. The  tube to be clean with no scratches on the inside.

Fig 1a
3mm Acrylic/Perspex Discs 50mm
purchased from eBay
Five discs approximately 4.50
Silicon glue gun  ( needs to be metal construction )
Shopping list of parts

1/  Silicone glue gun approximately  2.00
1/ Empty Silicon tube (free)
5/ 3mm Acrylic/Perspex Discs 50mm  (approximately 4.50)
plastic plumbing fitting  see image fig 2 (use the ends for mounting the die this  will clip onto the tube.)

Step 1 Prepare the tube and plunger
Step 2  make  die
My clay extruder is made out of materials lying around in my scrap box, I wanted to design a clay extruder so I could replace the dies on the end of the tube, with minimum cleanup.Simply load the tube with clay snap-on any of the custom-made dies then slowly pull the trigger to feed the clay through the die. To change the die I simply remove the tube from the gun clip off the die and replace it.
After finishing using the clay extruder remove the tube and wrap it into a plastic bag.  It is very simple to make, no mess, changeable dies, no clay seeps out.

Designed by Michael George Parry-Thomas

Fig 2
Home-made clay extruder
ick's Hobby Pottery