I would say it is a Model 10 also. Is it .38 special, or .38 S & W? Looking at the grips, I would assume it is a .38 special. They are not inter changeable. The .38 S & W is a very wimpy cartridge, which is why the Brits loved it.The .45 auto cal. model is much larger. And took a rimmed cartridge, and can also shoot the .45 Auto, with either, half moon clips, or full moon clips. It was not the .45 long colt. Although S&W does make a model to shoot the .45 long colt. For this gun,
I would only shoot standard .38 loads in it, not the plus P's, or Plus, plus P's in it. It will take it, but will loosen the gun, and will wear more. You have a very good, accurate, and serviceable pistol there. They were use by the nations police forces for years. Not the ideal defense round, but you can get a 110 grain, semi jacket hollow point, and it will make a good defense round. You can get the plus p's, but I would use them only for defense, and not for target, or casual shooting. Enjoy.
Wayne