to have a weapon that can safely chamber several different types of ammunition, for both economy, versatility, and if you are of the survivalist persuasion. Ruger makes a really nice double action revolver with interchangeable cylinders that can handle .22 LR or .22 WMR (the former is a lot cheaper). .357 and .44 Magnum firearms can handle the lighter .38 and .44 Special loads, but it doesn't work the other way round. I've always felt a good combination for deep woods or a marine "repel boarders" kit would be a .44 Magnum rifle and pistol, the latter loaded with the more manageable .44 Special load. In a pinch, either ammunition would work in either weapon.