Greetings Warbucks -
Due to the vast number and manufacturing v ariotions of revolver barrels, you might do well to slug your barrel and see what bullet *it* likes . :-)
However, if you have a revovler which actually states ".38 S&W ctg" on the barrel, the original loading was a .361 diameter lead bullet with a flat or slightly dished base. Several weights were comercially offered, 145 gr, 158 grain, 195 grain, and the 200 gr british loading (often called .380 or .38/200) these were usually round nose or a somewhat flat point.
hope this helps
yhs
Prof Marvel