I have a new model Bisley Blackhawk in 41 magnum 6"bbl that has been rather disapointing in the accuracy dept. I have tried bullet wts of 200, 210,Rem, GD & XTP, cast 240 and 255gr. with 4227, 296 and h110 The cylinder chambers have been trued .412 and trigger job done. Groups are around 3-5"@20 yds off a bench is there anything left to consider?