I always got the impression that a K frame magnum was a compromise so that police and security could carry a magnum capable revolver without the weight and bulk but in many cases they were loaded with less powerful rounds for daily carry. But they had to option to switch depending on circumstances. The durability of these revolvers is challenged by a constant diet of full magnum loads, per reputation. I don't know. Ask if anyone has ever shot one loose or cracked a forcing cone in their barrel with lots of hot ammo. Reports claim so but I do not recall seeing it for myself. I have a K frame magnum and also an N frame .357 which is supposed to stand up to the beating better, like the L frame revolvers.