Someone will correct me if I am wrong but the 38 S&W is the same diameter as the 38 special but the length of the special is much longer. You can try to insert a 38 special in the cylinder but it will only chamber so far as the cylinder has a rim that prevents it.

The 38 S&W was quite popular before the 1940's. I bought a new box about 10 years ago but haven't seen any of them lately.