I am trying to develop a reduce recoil load for my Springfield XDM in .40 S&W. I'm just looking for cheap practice ammo at the moment but may consider IDPA or other competition in the near future. I have 155 grain cast bullets, but may pick up a different weight if it's beneficial. What powder would you use for cast bullets with a reduced load? If I do compete it will be in the minor power category or production. I would prefer to not have to change recoil springs but get the recoil as low as possible. I only have the money for one gun for self defense and competition, so I'm not interested in buying a 9mm.

I have not worked with the Springfield but based on other semi's I've tried reduced loads with I would think new recoil spring.