A few years ago I called Hodgedon and asked about 231 in shotshells
They said absolutely NOT, so I have not used it for shotshells
I don't doubt it, but I'd like to know why. I'm curious that way.
I've only been at this since 1981. My reloading data is thus only fairly recent.
Back when there was such a thing as Hercules Powder, did they ever publish 2 1/2" loads with Unique?
Universal seems to me to be really similar in application to Unique.
Alliant has been dropping published loads in favor of publishing new loads for their latest and greatest offerings.
Example is how now they don't push 2400 for the 410, just (you guessed it) '410'.