I'm no expert here, but the 1911 is strong enough to handle pressures much higher than the 45 ACP produces. It is the 45ACP case that is the weak link. The case is not fully supported at the ramp point of the barrel and thus leaves a portion of the case that does not have steel enclosing it. The 45ACP case is too thin to handle very high pressure because of it's wall thickness.
The 45Super, 45SMC are externally the same dimesions of the 45ACP but have thicker walls designed to handle higher pressures. These cases can produce pressures much higher than the 45ACP.
How well the 40 performs in the 1911? Not familiar with it.