When you say "soft bullet", do you mean a bullet that expands quickly? If so, there are a lot of choices out there. Powerbelts tend to expand quickly, even at low velocities. If you're using sabots, you have lots of options - pick a bullet that is all lead, as opposed to a jacketed round. Cheapshots, Buffalo Bullets, Dead Centers - all of them are lead and expand quickly. As for accuracy, it depends on your rifle - the only real way to know is to try out several brands/weights, etc. and see what shoots well.