OZ, round up some factory .38S&W loads and have fun! I came into possession of a pair of the early .38 top breaks (spur trigger version) that I have fired with the factory loads. It is indeed a hoot! In my opinion, the .38 S&W loads are light enough even to shoot in these older guns,and as opoefc said, you will be amazed at how accurate they can be. Nice toys for older boys!
MikeyL
S&WCA #2010