I use 100% plated bullets, since the ranges in these parts don't allow lead. Currently, Xtreme 125 gr flat points.
For light loads, I use a maximum jigger of TB, with good results. A lesser load gives poor accuracy, which likely means poor obturation. Plated is more like hard cast, even though the lead underneath is dead soft.
For plus P, and light magnum, I use A#5.
Generally, I shoot the TB loads in my M442, and the A#5 loads in my K and L frames.
Accurate Powders gives some data for plated bullets on their website. This seems to be somewhat unique.
A#5 does not do well in lighter loads. Unburnt powder made extraction very difficult with my late M640 with minimum loads. No more.
Unfortunately, I just finished my bottle of TB and have very little A#5 left. I do have a jug of PB, and then its black powder!
Best,
Rick