[Unclenick]

For conventional pistol match shooting, get 200 grain cast SWC's in the popular H&G 68 shape for Slow Fire, and most anybody's hard cast or plated 185 grain SWC for Timed and Rapid. Get the square base rather than a bevel base design. In a revolver I think you'll find the bevel base offers the throat a little more time to bleed gas through the barrel/cylinder gap, so you get a little more top strap leading and maybe a little more sensitivity to a throat constriction where the barrel screws into the frame. The square base also spends less time clearing the muzzle, so it's less prone to muzzle blast-induced yaw and drift. Get a Lyman M expander die, as their step profile helps any brand seater put the bullets in more straight, and that actually affects group size, I've found.

When revolvers were still prominent in conventional pistol matches, 3.5 grains of Bullseye powder was a common match load and will work well with both the bullet weights I mentioned. If you can find a seating die for .45 Auto Rim brass it should have a roll crimp rather than a taper crimp. That shortens brass life, but the old timers swore the heavier crimp produced better accuracy, so that's something you can try. I see a reduction in MV variation, and for those slow-moving SF loads, when you shoot the full 50 yards rather than reduced targets, that can help. It shouldn't matter for Timed and Rapid.

Use Federal 150 or 150M primers if you get the mainspring lightened at all. They still seem to be easiest to ignite.