KLRANGL... I am including info on the 'primer actuation' principle along with the Garand that John C. designed. A schematic is available and I will post it, if you like, but it is quite difficult to read.
You should know that, along with the 'primer actuation' style, another type the 'Bang' principle, which involves a sliding muzzle cap, was also being investigated by the Ordnance Department.
If you would really like an education of the first totally reliable semi-automatic and full automatic firearms... hie down to the local library and pick up a copy of John M. Browning, American Gunmaker. I read this book about once a year for true inspiration.
Here is the information you asked for along with Browning's first semi-auto: