[260 Rem]

Obviously, different shooters prefer different media ... and matching equipment to needs is important.
After I started shooting at paper from a bench it did not take long to realize I had much to learn so I started soaking up “advice” from shooters I observed that were getting “better than mine” downrange results. As much as I asked “how”, I asked “why”, and in time I was able to shoot as well as those whom I emulated. My point being, it is important to understand the mechanics behind “why” one “practice” trumps another.
With respect to bags, I get best results with a “bag” that is “firm” as opposed to “hard”. The bag needs to be filled with a medium that will retain shape. In a “sporter” style front bag, the rifle first slides under recoil with a tendency to roll to the right..and as the butt comes to a stop (center of the stop resistance is lower than the bore), the rifle rises and then drops back onto the rest. This results in some “pounding” to the bag which must be hard enough to resist changing shape or else the slide path will change from shot-to-shot (that difference eventually shows up on the paper downrange). In this case, what media will resist deforming? Will it be sand with small irregular shaped crystals that will lock tightly together OR will it be steel shot which is round and acts like a bunch of ball bearings with voids in the non-contact surfaces?
And then apply the same idea with what occurs with the stock in the rear bag.