I am a novice and offer my data. Work your loads up carefully. I used Varget 29.5 in an 8-twist Shilen 6mm BR with Berger 105 24428 and BR4 primers. Results were SD 9.2, ES 24, speed 2863.1 f.p.s. avg. for 7 shots. I can't find the group size, it was at 200 yards, it would be less than an inch.