Okay for light loads in .38. I'd go a lot slower on the powder for .357, start with maybe Blue Dot. I use 2400 mostly, myself, and AA#9 is a modern powder that works really well.
My .38 powder is Bullseye, slower than Red Dot, but still really fast and dense. With Red Dot as with Bullseye, be very careful not to double charge a case. That can be catastrophic. I might try a pound of trailboss in the future for light loads, but I'm not sure if it'd work with wadcutters. It's very bulky, but it prevents double charges by the fact that you can't fit a double charge in a case, yet it's fast burn for light loads.
Red Dot is not a powder I use. Trap shooters like it for light shotgun target loads. It's just a bit fast for me to like it. Also, didn't mention, but W231 is a very good powder for .38 light loads and W296 works equally well for .357 hot loads. I've got a friend that likes the Winchester powders because they're ball powders, like the AA, and meter well and burn clean. I've just standardized on the old standbys, Bullseye for light .38s, and 2400 for hot +P and .357 magnum. I also use Unique in hotter .38 loads, is a good powder. It all works, that's just what I use and I'm old and set in my ways.