I've been looking through old load manuals, trying to tweak some of my .38 Special and .357 Magnum loads with the powder I've been able to find in stock. I found that the load data in Alliant 2005 is just carried over from Alliant 1995, which is carried over from Hercules 1992. But there were big changes in the tables between Hercules 1987 and Hercules 1992. For example,
Hercules 1987 has the following for .38 Special 158 grain RNL:
Red Dot: 4.0 gr for 925 fps
Unique: 5.5 gr for 980 fps
Hercules 1992 has the following for .38 Special 158 grain SWC:
Red Dot: 3.1 gr for 835 fps
Unique: 4.3 gr for 920 fps
Those are drastic reductions in powder charge! Why the difference? Were the powders reformulated, or the testing equipment changed, or what?
Snapshot of the pistol page from 1987 and 1992 attached.
Thanks,
LBS
Hercules_1987-1992_Pistol_Compared.pdf