for a .22rifle, its basically to improve..
group size and to minimize outside variations.
I made a new walnut position stock for my Anschutz, I made pillar for both the action screws. The front also had an "recoil lip" for entering the cross-action slot that had a separate cross bar in original prone stock.
Bedded theses pillars in and clamped the action in-place, then did a full action bedding. Final bedding was where the barrel/action joint was located, here I bedded the expose action front and two inches of barrel, when the un-used bedding started to set, I inverted the assembly, to allow the barrel to hang away, allowing the bedding to flow and form. Cover that area with duct tape.
After 24hour drying, removed tape and cleaned up, now the barrel has a formed bedding block that supports the barrel in a positive manner and effectively "free floats" thru its vibrations.