Ultimately the toggle link is the weak point in the 60/66/73 design. Though modern metallurgy is better than the original brass and iron used in these designs
Rearward bolt thrust varies from cartridge to cartridge, depending on surface area of the cartridge to chamber contact, chamber shape, friction, bullet weight, etc. For every action, there is an equal and opposite reaction. Pressure is only one consideration. The heavier the bullet, the more rearward thrust. Some case designs cling to the chamber more readily when the case expands against the walls. Rate of powder burn and pressure curve of the burn, etc.
Most of those old cartridges are limited in pressure more to protect the original arms they were chambered in than limitations of the components available today. Remember, these were originally black powder offerings. Some of the cases are thinner as true to the original design.
Without considering the rifle, the .357 cartridge itself and the components used in it were designed to operate under higher pressure.
Last edited by Frontiersman; 12/09/18.
