I realize this threads over a month old, but since we've started making clay pipes in addition to our cobs, I figured I'd add my two cents. There are basically two methods for making historical colonial era clay pipes, by hand or by press mold. Most of the white clay pipes that people normally associate with the 17th and 18th centuries were press molded clay pipes typically made in brass/bronze, wood,or cast iron pipe molds. The clay would have been rolled from clay balls into "rolls" that were placed in the 2-piece mold and pressed in a gin press. A special tool called a "stopper" was then inserted into the bowl end of the mold from the top to shape the bowl chamber. Finally, a wire was inserted through the stem end of the mold until it punctured into the base of the bowl (some manufacturers would run the wire through the stem end of the roll before placing it into the mold). The "molded" pipe was then set aside on a drying tray (often referred to as a dozening board) to dry before "fettling" (process of removing the extruded seam clay in order to give the pipe a more aesthetic appearance). It's very easy to accidentally break a pipe during the fettling process as the clay is still very green at this point and the pipes are extremely fragile until fired. Once completely dry, the pipes were then bisque fired in a kiln (typically we fire our pipes in the 1,760-1,830 degree F range).
The other method, by hand, is typically associated with Native American pipes as well as "Colono" or "Chesapeake" pipes. The red terra cotta Colono pipes are somewhat of a mystery as archaeologists and pipe historians still argue whether or not these pipes were made in the Colonies by English colonists, Native Americans, African slaves, or a combination of all three. The Colono pipes were typically rolled by hand but made to closely resemble European press-molded pipes of the period. They were often highly decorated with symbols or geometric patterns pressed into the clay such as by using cording or twine wrapped around the bowl and stems to create a "rope" pattern. White clay slip was often added into the impressions to highlight the decorative elements. Colono pipes are typically associated with the 17th century and pretty much disappeared by the beginning of the 18th century.
Anyway, hope this information was useful.