I've been studying factory 38 Special +P "Chicago" "FBI" etc. loads lately...basically +P loadings with a LSWCHP.
Remington, Winchester, and Federal all continue to produce a version, however, Remington's was noted to use the softest lead...a sort that could be dented with a fingernail easily. I sincerely doubt it was truly "dead soft" or pure lead as some claim, but what seems to be the consensus is that the newer loading which goes by the HTP name (last few years) instead of Express uses a harder bullet and consequently doesn't expand at the sub-900 FPS velocities typical of snub nosed revolvers.
I was considering using a gas checked bullet with a very soft alloy (like 1:30 or perhaps even less tin) to see if it would be possible to get expansion at very low velocities.
I was thinking it reasonable to take soft castings from my RCBS 358-158-SWCGC and drilling a hole with a center-drill for the nose. This would bring it under 158 grains for sure, which would make loads for the Lyman 358156 a good source of data...like 5.4 grains of Unique from my Lyman 4th.
But I concern I had was leading and consequent accuracy loss.
Has anyone experimented with alloys this soft and using gas checks to make up the difference?