Word of the "do not use in handgun loads" hit the SASS Wire several weeks ago; where Nitro 100 is very popular for light loads in .45 Colt, etc.
Bear in mind that Accurate has gotten powders made under contract all over the world, starting in Israel and including Communist China, the USA, the other USA (Union of South Africa), and the Czech Republic. There is a thread with pictures of AA #5 from different powder mills but claiming the same load data.
Accurate was bought out some years ago by Western Powder Company who has kept the Accurate lineup in place separate from their own Ramshot powders. They have recently gone to American sources for Accurate powders, note the "made in USA" on the "no handguns" labeled Nitro 100. Their ball process powders like AA #2, 5, 7, and 9, etc. are now made at St Marks Powder, home of the Winchester Ball powders. I assume their flake and extruded powders are now contracted at Alliant; I do not know of another commercial powder company left in the states. (IMR is in Canada.)
I will be sorry to see Solo 1000 dropped, I was just getting comfortable with it in pistol loads.