The purpose of this video is to describe a hand priming tool that is not rim thickness dependent: the Sinclair hand priming tool (older version relative to the one in production today). The Sinclair had minimal total cumulative error similar to the Lee ACP which is another tool that is not dependent on rim thickness. There was no correlation between seating depths produced by the Sinclair and rim thickness and primer pocket depth. We will continue to evaluate priming tools to assess what factors (if any) affect seating depth with the particular tool.