I also know a few who lil gun is the go to powder for the 357. I am sure it is on the data sheets and loads from the maker.
Lil'Gun loads are listed for 357 under pistol loads on the Hodgdon website. I use those for rifle and they work great.
That's interesting...I would think Li'l Gun would be a nearly ideal powder in this combination, but there isn't any data listed for the 140gr FTX. I wonder if it was included in the FTX Load Notes that Hornady had online for a while?
Now, that being said, I do not use Lil' Gun in revolvers. There have been some serious reports of premature firearm failures when doing so. I AM NOT saying that they are true, I just don't want to find out if it is on any of my firearms!