7mag, i'm gettin holes touching at 50 yards with 5 shots. ive only used remington@ hornady shells. if u do buy it i recommend taking it apart and replacing the spring on the trigger with a ink pen spring. it's easy 2 do, just take the screw out holding the trigger in-,get u a pair of wire cutters-, set the 2 springs side by side-, and cut the ink pen spring 2 the same size as the spring that was in it-, set the spring in and screw the screw back in. u will go from about 5lb pull to about 1to 1lb and a half pull. let me know if u get it and try it....keep me updated!!!happy shootin!