While initially reading through AFMAN 36-2201, you may skim across the information and accept it at face value, however, if you look deeper into the Face as in Marching, you will see there is a problem.
The Problems of AFPAM 34-1203
After the USAF was created as its own uniformed service on September 18, 1947, it went from using Army Regulations to writing and using its own. When it came to drill and ceremonies, the newly created service looked at the Marine Corps and Army drill manuals and chose from what it considered the best from each (most from the MCO). One thing the USAF eventually left out (beginning in approximately the 1970s) was the manual of arms for the rifle. Why? Because the Army and Marine Corps had already accomplished that task and Airmen did not have a daily use for rifles like Soldiers and Marines.