Alliant still makes Herco although many of the loads have disappeared from the modern load books.
I use it in 380,, 9mm, 38/357 38 Super, 44 S/M and 45 acp. It's great for filling the case up and getting higher velocity at book load levels than many other powders. Can't easily double charge it unless your using a big case. I use it to push 9mm JHP to +P velocities without approaching the book max load (at least some of the older pre-2000 books).

I just used the last of some old stock that was in the tall cardboard container (circa 60's & 70's) and bought some in the new plastic container. I had enough of the old left to do some comparison loads in 44 Mag and the new stuff ran about 50fps faster.

ps...
That 38 Super load has got to be hot hot hot, as even Speer # 8 only lists 7.5 as Max. However they do list 8.5 for a 100gr. I know back in the 80's the IPSC guys pushed the Super well beyond any book maximum.

Speer #11 is a little bit more informative in that it specifies a max of 7.9 for a .355"TMJ, 7.5 for a .355 JSP and 7.0 for a .356" 125gr - this last one is odd, as they list it only as Round Nose but don't say if it is Lead or Jacketed. The picture shows what looks like a canneluer ring but is more likely a lube groove since none of their other jacketed pics have the ring and the dia is +.001".