Here is a cell phone shot of the M-1Dimage.jpgimage.jpg
Although this is in "An Endless War 1968-1969" I think it is much earlier because everyone else has M -14s. They look like Marines. (No high viz US ARMY and name tags). Ed Kugler, in his book DEAD CENTER, recalls that the USMC offered the M-1D to snipers but it wasn't popular due to accuracy issues.