I'd recommend replacing one of the recoil springs with a lower power version BEFORE modifying any bolts etc. Only because you can easily swap it back if it doesn't help.
Also, My 3gun S12 will run value pack bird shot all day long, but I tried using reduced recoil slugs, and they short stroked. Those things are BABY loads.
1 1/8oz, 3dram bird all day or Remington Sluggers 2 3/4.
Shy away from the reduced recoil.
Also, Shotguns don't have extremely hard primers, so a lower power hammer spring can maintain reliability while reducing the energy needed to cycle the bolt over the ha