Anyone remember Scot Solo 1500 powder?

[Tugnut]

In my quest to go against the grain and find the quietest sub loads possible that will still cycle an AR, I've tried some oddball powders.

For example, I could get 800x to cycle, but no BHO and just .2 gr could be the difference between a subsonic and supersonic load. Fail.

When I started handloading in 1999, I bought a pretty good stash of Solo 1500 for dirt cheap and I still have a bunch of it. Seeing as to how it's close in burn rate to N105 and is a clean burning, single base powder, I decided to try it. I took a guess where to start and tried 7.6gr under a 168SMK. It was really quiet and ejected the spent case, but didn't feed the subsequent round. 8.0gr cycled and sounded great, so that's a good start. More testing needed.

So two questions. Have any of you ever used Solo 1500? And is N105 a single or double base powder?