One thing that I considered regarding the bushed pins is that it seems, to me at least, to be something very complex and not very easy to change from an integral striker to a bushed pin. The geometry of the pins in relationship to the original strikers have to be considered. Any mistake and your action is gone.

The diameter of the vent in a double rifle with bushed pins are so small when compared to the diameter of vent holes in a 98 Mauser bolt, for example. Will those small channels be enough to divert hot gases?

Anyway, I have to aggree with Colorado. For me, it seems a better approach to keep your loads on a safe margin and avoid the overpressure by all means, than try to discover the limits of strength and safety of your gun action .

Fred