Just MHO, but Hodgdon made a HUGE mistake in the NAMING of the Clays series of powders! Therefore, I use ONLY the front name, i.e., "Clays", "Universal" and "International". This avoids confusion which could prove disasterous. Hodgdon's powders are similar though not completely equal (ALWAYS FOLLOW THE MANUALS PUBLISHED BY THE "MANUFACTURERS"...Hodgdon's powders in this series are actually made in Australia) to ATK (nee Alliant, nee Hercules) powders. In other words Clays ~ Bullseye; Universal ~ Unique; International ~ I'm not sure...never used International. As I said, however, follow the manuals!
I would definitely AVOID reduced loads of Unique or Universal in large-capacity cases like .45 LC, .44-40, etc. Trailboss was developed to more fully fill these cases, though it has apparently proved to be somewhat temperature sensitive, and I would NOT use the lightest listed loads with bullets lighter than 230 grains in .45 LC.
BTW, HP38 is identical to W231, although AS WITH ANY POWDER, there can be lot-to-lot variations that should be checked when you buy a new container with a different lot number than another. Incidentally, in the past, I have found Universal to be VERY UNIFORM lot-to-lot.
[I cannot be responsible for the use of the above information in guns other than my own, and maybe not then! Usual disclainer.]