Re: Prone Shooting with Sling,
Basic marksmanship training should always include some sort of demonstration of both the hasty and loop sling. The first element of a steady position is artifical/bone support, and, being more a support than a rest, the sling may be more ideal than the bipod, as it allows the shooter greater control over the rifle until recoil has subsided. It's the partial control afforded by the bipod which makes its use suspect, since some muscular effort is required to get consistency from trigger pull to bullet exit. With proper sling support the body can relax into the sling for complete muscular relaxation. Complete muscular relaxation inspires a very consistent angle/arc from line of bore at rest and line of bore at bullet exit. Also. the sling can be better when bipods are simply too short, like when a hasty standing shot is all you've got. The bottom-line is learn how to use the sling, you never know when it could be better than alternatives.
BTW, the sling and the bipod are somewhat opposites. The bipod is more exact before trigger pull than the sling, yet, the sling is more exact after trigger pull. That's why I'm prone to use the sling-forgive the pun, I'm just more concerned about control after trigger pull than before, since anything not consistent after trigger pull leads to angular error which increases with distance. Since the wobble before trigger pull is not angular, having a wobble free position, as allowed by the bipod, is simply not as important to getting a good hit as may be assumed.