Red dot for subsonic loads
 

I tried some in my Savage just for S's and G's. My findings: Dont! With a 240 Matchking, 6.0 grains blew out a primer. 5.0 grains gave me ~800 fps, and the bullets were sideways at 100 yards. I also tried it with some 155 Matchkings subsonic, which worked, but not well. With 5.0 grains, I was getting right at 1000 fps, but accuracy was not good. I'm still waiting on my stupid suppressor, but all loads were noticeably quieter than the 8.5 grains of VVN-110 that I usually use. My next experiment will be to try something in between Red-dot and 110 on the burn rate chart, with the hopes of a quieter subsonic load.
-Dan

For something that's not being run through a semi-auto, I've found AA#2 works very well.

Any of the faster powders should sound better than a slow powder (like N110). Slower powders require more powder, which translates to more gas volume for the silencer to deal with. The down-side of using a faster powder is that pressures rise more quickly, so smaller variations can get you into trouble sooner.