Alan:
I have never used a 200-grainer in the .357, but have some experience with the 180-grain Speer silhouette bullet. It may still be sold as a 'FMJ Flat Nose', though the jacket is much thinner than military-type 'ball' projectiles. Its not really a flat-nose in the usual sense, either, being fairly pointy with a small flat meplat like the current crop of 'protected-point' bullets. Speer Product Number was/is 4229.

My load is 10.35 grains of Blue Dot, which averages 1205 fps in a S&W 686. I carry this revolver for protection against feral stock and dangerous wildlife while conducting field survey work in remote areas, and the load is as close as I can get to a potential short-range 'stopper' for scrub-cattle, buffalo, or crocs in the .357.

Warning: this load is stout in my revolver, and is probably close to maximum. It is not for every-day silhouette or range shooting, or I suspect the 686 would become very rattly in short order! As usual, start well below and work up...

Again, sorry I couldn't help with the 200-grainer.