When shooting off a bipod,the rifle doesnt need a support hand,(other than using it as a fist to hold up the but end of gun.)
We often shoot man v man on metal plates at 400yards.were speed is important.The right handers have to remove their hand from pistol grip to operate bolt !I dont.get it now.?some right handers adopt a technic were they trigger the gun with their middle finger,as they close the bolt with their thumb n fore finger.