I was looking back through my most recent stack of American Rifleman mags, re-reading an artical in the July 09 edition. One of Garands first attempts, "T1920" used what was described as a primer-actuated mechanism. The artical does not describe what this is. Does anyone have any links to articals giving a detailed description with illistrations or drawings explaining this operating device? I was just really curious about this evalutionary step.