bullet shape for speedloader use
Chamfer the charge holes in the cylinder. That helps.
I shoot a S&W 15 in SSR class in IDPA matches once in a while. I use 130 grn RN-FMJ bullets in that application, because they work better with a speedloader. The round noses on the bullets make the rounds slip in a little easier and the jacket reduces problems with leading.
You can only learn from experience if you pay attention!