OK, although I am new to the forum, I thought I would stick in my 2 cents worth. As a retired police firearms instructor, I feel that I may be able to shed a little light on this never ending debate.
My first duty gun was a Smith model 10, loaded with Dept issued 158 gr. swchp +p (Winchester). A very effective load, and easy to control in a 4" revolver.
My 2nd duty gun was a Smith mod 36. Same load. I know that this is not reccommended by Smith, but I personnaly know of no problems concerning its use in this gun. Practice with target loads. qualify with street loads.
I now carry a Smith 642 loaded with 110 gr. sjhp (Remington).
As you can see, I have no problem using the old .38spl. for self defense. As a matter of fact, the theory of the "one shot stop" is, in my humble opinion, a joke. If you are willing to fire only one round in defense of your life, get a Barrett .50. Since the purpose of any self defense gun is to STOP, rather than to kill, or wound, you had better get in the mind set required. You keep shooting until the threat is eliminated. Subject down and no longer a threat, or disarmed.
Sorry for the lecture, but I see no reason to consider the old .38 anything but adequate.