Say what?!
My left is providing 99% of the support against gravity.
There were those that would advocate what IndyCA describes, but my sense was it was more individuals or pockets than doctrine. Jim Owens (USMC ret.) describes a stunt that one team shooter would perform for training classes, where he would walk in holding the rifle in the firing position with just his right arm. He acknowledges it had no bearing on a good scoring position.
You're looking for documentation when there might be none available. Time to dig out the old military training manuals, and marksmanship texts.
Why may I ask does it matter on the why?
