[Archie]

Alan, if you're concerned over lead deposits, you may want to see if any dealers have 'plated' bullets. They are cheaper than jacketed, but resolve the lead bullet issue. When you're done with your current stock, of course.
I shoot lead bullets out of all my revolvers and don't have any serious problems; but each revolver is a law unto itself.

Mike, sheesh!
I think I did my first reloading for 38 Special during the Nixon administration. You are correct in that there may be 'new' powders more suited in a number of regards for 158 grain 38 Special loads; however, the basic principles have not changed.
And, in Alan's first message, he limited his question to Bullseye, Unique and 2400.

What has not been mentioned is that "heavy loads" in a 38 Special are pretty archaic. .38-44 Outdoorsman revolvers notwithstanding, the .357 Magnum has pretty much ended the need for .38 Special heavy loads.
I did my experimentation as a younger adventurer who didn't have a .357 magnum. Got some pretty impressive loads, though.
The liability lawyers no doubt have had some small impact on loading manuals and corporate thinking on such matters. Lord preserve us!
Also, I understand many powders burn 'faster' these days. I do not understand why that should be so. Still, we've always known powders vary lot to lot. Perhaps 2400 is a different powder than it was some 30 years ago.

To be honest, my 38 Special loads these days are pretty much WC loads for PPC and bullseye shooting and some SWC rounds for the distinguished matches. Oh, and I load a practise round for the 158 SWCHP lead bullets I carry in my M10 anywhere gun. I load all those loadings with WW231.

But you're right, things have changed. I used to test my loads at the dump. Unsupervised. Amazing.