The Super is physically the same size as the 45 ACP but it uses cases cut down (or custom made) that are thicker and heavier in order to withstand much higher pressures. The complete conversion includes a barrel with a fully supported chamber (the bottom of the case will be blown out if fired in the usual unsupported chamber), heavier recoil springs, a new firing pin, and the ejection port must be enlarged because the slide moves so fast with this much recoil energy that jams occur without making the window bigger. I suspect that regular 45 ammo could be used in a converted gun by changing back to the normal recoil spring, but I am not positive as the firing pin may not work. Anyway, never even think about firing Super ammo in a normal 1911.