I typically use 148gn WC for my 38 practice rounds. Was at a gun show last weekend in PA and a dealer said that I might like to try 100gn lead wad cutters. Little did I know that I would have trouble with finding a load. Lee manual says 148gn WC is good with Bullseye from 2.7 up to 5.7gn loads. Quite a range!

I have two choices for proceeding. interpolate the 125gn vs 148gn cast bullet loads or ask the experts on this site.

So what do the experts think?
target load around 1000fps and use is in a stout revolver ala RUGER Blackhawk....

I think 5.7 to too high a load!
Lyman list bullseye, a92gr bullet 3.3 to 5.3grs 1110f/s.
I would start at about 4.0grs and work up in .01 or .02 grs at a time.

If these are soft swaged bullets stick to the minimum charges listed. Drive them too fast and you'll have a mess to clean up. BTW, they make good varmint bullets too.