I noticed a post on a local forum where someone had purchased an old S&W revolver marked “S&W 38 CTG” and had purchased some 38 Special cartridges for the firearm. To make it even worse he had purchased +P. Let’s start there with a quick lesson. Only guns marked for +P ammo should be fired with that ammo or guns which state it is ok to use in the owner’s manual. The safest thing to do if you do not know is to NOT use +P ammo.
This person found the ammo would not chamber in his pistol which is a good thing. Mike Hudson has a superb article on the cartridge entitled Consider the Forgotten .38 S&W which does a much better job of covering the ammo that I could ever do.
The photo above is from Wikipedia and one of the issues with this cartridge is finding the ammo. I checked a few web based retailers and those who do have the ammo in stock generally only have one single manufacturer and type so there is not the wide variety found in other calibers. Bottom line is if you purchase a firearm, be positive about the ammunition it requires before you purchase anything. Ammo is generally not returnable so that poster is now stuck if he does not already have a 357 or 38 special. On the bright side it will give him an excuse to purchase one so he can shoot the ammo!