I have an SLP Mark 1, and I shoot 2-3/4 dram, 1-1/8 ounce loads. Typically shoot the Federals from WM, but have also had good luck with Estate. My gun hates the 1600 fps, 1 ounce slugs. I need to find some 1400 fps, 1 oz to try. Managed recoil buckshot is not potent enough to cycle reliably. Hope this helps.