Probably not an issue for bottom feeders as you hardly ever have to reload, but I'm in the habit of taking the left knee down for reloading. With the left knee up the muzzle comes real close.
The usual advice is to take the right knee down to the side of cover, thus making it not obvious to the SO if you are in or out.
The usual advice is to take the right knee down to the side of cover, thus making it not obvious to the SO if you are in or out.