On two occasions in the past, I attended classes with local instructors for defensive shotgun, and I've tried to learn as much as possible from reading and videos, etc. One point that the classes made, is that there's a lot of virtue in being able to shoot well with the gun on either shoulder. This enables maximum concealment/cover when moving around corners that open to one's left, or right, by shouldering the gun on whichever side is the first exposed. Reloads seem a lot easier when shouldering on my weak side. Of course I'm still faster and more stable shooting from my strong side. Do most folks put much focus on shotgun training from both shoulders? I have a Mossberg 500 and a Remington 870. I've really begun to appreciate the controls on the M500. What is one supposed to do when shooting an 870 off of the left shoulder - that is, how is the safety supposed to be controlled, with the left hand on the grip?