Here is a composite image showing two 50 caliber large frame Ideal #6 tools. Can you see the difference in the way the tools are configured? Obviously, the top tool has an adjustable seating chamber and the older 50 Gov tool has no bullet sizer, but can you see the more fundamental difference?....The tools appear to be mirror images of each other. The reason is that the casting chamber has been cut on the opposite side of the blocks, and the sprue cutter has been placed on the opposite side too. Notice that the sprue cutter swings toward the seating die on most Ideal #6 tools, but the "left handed" variant (illustrated by the bottom tool) has the sprue cutter swinging away from the seating chamber.