Pillars 101:
This whole thing started a few decades ago when wood was more prevalent as a stock material. You snug up an action and over time the screws back out. Why? Wood is organic. It swells and shrinks with weather. Compound that with the level of vibration that takes place during a shot string and you end up with screws that misbehave by coming loose.
The pillar idea came about as a means of mitigating this. With the mating parts now suspended from one another by a steel/AL column, the problem goes away. The nature of shooters is "more must be better" so the practice continued once synthetic stocks came into everyone's viewfinder.
In today's stock making the composites have more than sufficient compression tolerance for 50 inch pounds spread over a broad surface area. (action/floor plate) The "carbon thing" is largely irrelevant. You could shell a stock in paper mache and it wouldn't make much difference in that context. Look at stuff closely once. Anywhere there is carbon, is by and large not contacting the action or related furniture in a relationship that would influence this in any appreciable way. It's all cut away. The shell is just that. A containment vessel shaped to be ergonomic and pleasing to the eye.
It's primary job is to add stiffness and tolerance to recoil as it wanders its way back to your shoulder. The core of the stock is doing the work of transferring this energy to the shell. So long as the materials used have sufficient compression tolerance, it tolerates the loads put to it just fine.
-That said we still use pillars on everything because the consumer expects it.
It's not until you begin laying up much more complex mold/bladder structures that this changes a bit. You have to first divorce yourself from the conventional "hard boiled egg" rabbit hole to accomplish this. Not a cheap or easy venture.
C.
