I use 250 grain shockwaves with 2 -50 grain pellets. They hold tight groups out of my remington. There is a differece in the way Shockwaves are packaged. The black sabots have 3 petals and a smaller base for loose powder and smaller loads. The Yellow sabots have 2 petals and a deeper base for pellets and magumun loads.
I have found the yellow sabots do seem to group alittle tighter out of my gun.