Bailey Clay Extruder
http://www.dickblick.com/zz302/34/products.asp?param=0&ig_id=4516is recommended for solid clay shapes up to 3" (8 cm) round tubes or 33/4" (10 cm) wide slabs.
It features a square barrel, a heavy-duty quick-change die holder, and a plunger stop to protect die braces from damage. Mount it on a wall or table. Includes mounting hardware, one coil die, two blank dies, and instruction booklet. Barrel capacity is 11 lb (5 kg) of clay.
http://www.dickblick.com/zz302/34/products.asp?param=0&ig_id=4516