As an owner of three SP101s in .357 and many S&W J-frames in both .38 Special and .357, I'll offer my opinion that unless the gun is to be used mostly by someone very weak and small, employing an SP101 for anything other than .357 is a good example of "size inefficiency" (term as applied to CCW).
Many better, smaller, lighter weight, more compact dedicated .38 Special gun choices are available if you mean to carry and shoot only .38 Special (including "+P") rounds. Dedicated .38 Special SP101s are made, but are getting hard to find, while .357 models are readily available, but are a suboptimal choice for shooting .38 Special for two main reasons: the increased space between bullet nose and forcing cone can reduce accuracy in shooting .38 Special rounds, and the accumulation of firing residue in the cylinder chambers' free space after shooting much .38 Special will make subsequent chambering and shooting of .357 ammunition difficult and even potentialy dangerous, unless you assiduously clean out the chambers beforehand.
If you're determined to shoot only .38 Special and to use the gun for CCW, I'd suggest an all-steel J-frame. If it's to be mostly a range gun, then a .38 Special Ruger SP101 is a good choice, as also are many other larger, heavier revolvers from S&W.
I don't carry or shoot anything but .357 in my SP101s. If I mean to carry a gun in .38 Special, I usually choose a Smith pre-lock 649.